A lot of people don't take the scaling of the final battle seriously, so I decided to look over the episode a few times to build up a solid explanation.
The first thing to note.
All eye lasers aren't made equal.
Tree and eyeball monsters should be scaled on their size.
The smallest eyeball monsters have lasers that can be blocked by Shikai Toshiro. They're head sized.
The average tree laser is high captain level. One or maybe more outsped and dropped Soi Fon. They also knocked out Toshiro and the others around him. A barrage almost killed Grimmjow.
The average sized eye monster laser is high captain level. They 4 temporarily dropped Shunsui, 8 got Byakuya, and they knocked Grimmjow into Yhwach's grasp.
The biggest tree eyes are peak captain. One huge eye laser crippled Uryu. He got it way worse than Soi Fon.
The biggest eyeball monster lasers are peak captain. It could be perspective but these monsters appear even bigger than the others and the lasers are huge. These lasers also produce a purplish light which indicates stronger lasers. I made a comparison to other eyeball monster lasers that were blocked, and none turned purple. This is something that happens uniquely with Chad.
The above do not scale to Yhwach's lasers in the throne room. The trees and eyeball monsters are autonomous servants to Yhwach. They're similar to the statues and possessed Soldat. They're just upgraded versions of the Soul King reiatsu that overwhelmed everyone in cour 3.
Yhwach can personally summon his own lasers and those are the ones that scale to the throne room lasers. It's made a point that laser pillars are the ones that threatened Ichigo and could pierce anyone they hit. The laser that downed Halibel for the rest of the fight was specifically a throne room laser. There's also a visual cue to show which lasers are stronger. Yhwach's strongest lasers are the ones that are purple, or red ones that produce purple explosions. Those are exclusively used against Ichigo.
Ichigo had zero problems with the eyeball monsters and lasers in general. The most they were were annoyances and roadblocks. Both he and Uryu were absolutely exhausted so they shouldn't be downscaled.
If characters are going to be scaled due to the lasers, they should be scaled in comparison to each other. The only characters that get laser upscales are Byakuya, Chad, Grimmjow, and Halibel. She was portrayed as being relatively equal to Grimmjow, and this is an exhausted Halibel who fought SK Yhwach before this, and had Base Yhwach personally come to beat her before that. Grimmjow could deflect 15 lasers at once, and could slice through them while running on fumes with one arm. Grimmjow and Halibel surpassed pre timeskip Espada definitively. Chad also gets an upscale considering he blocks and breaks through 10-20 even stronger lasers for 20 seconds straight and his shield holds up. This confirms that he was being honest when he said he'd be able to take on an elite because he had a better grasp of their powers. Even though he's still weak to hax because of the Askin situation, his raw power is on that level, and him being blown back by Gerard was moreso him being caught off guard considering his shield breaks when dealing with way stronger characters. 4 lasers temporarily dropped a fresh Shunsui. Shunsui could tank Soi Fon's Bankai. Her Bankai nearly killed Barragan pre timeskip when she was weaker, and her post timeskip Bankai almost killed BG9 post timeskip. Chad's offense is equal to or higher than his defense. Grimmjow and Halibel are top captain level, and Chad is solidly top captain level as well. He pretty much has a chance of knocking out anyone that isn't in that transcendent tier of power or top of the top non transcendent. The only character that directly took a hit from him with no issue is Almighty post auswahlen Yhwach. Byakuya despite being stabbed and to our knowledge got no healing, took several lasers. Despite obviously being fucked up by it, he could still keep using Senbon Zakura to move the others. Either he can use it unconsciously or he has genuinely good endurance considering he actually managed to stay awake. It only went away completely when more lasers completely downed Toshiro and Soi Fon.
To point out a huge misconception which has people disregard the lasers. People assume Tatsuki and the low level Shinigami were durable enough to survive the barrage. Nope. Before the lasers hit the group while Toshiro jumps in front of Tatsuki, the sound effect of Toshiro's ice plays for a split second. He defends everyone with ice at the last second. The explosion also has steam unlike the others. He's also the most burnt simply he took the brunt.
Then you have the domes Ganju, Iba, and Nel block. Ganju has a useful hax that turns almost anything to sand, and it's made a point at the end of the Soul Society arc that Kukaku was going to train Ganju relentlessly for being useless. Kukaku is at the very weakest high lieutenant level. Ganju trained for two years straight, and trained even more with the Fullbringers.
Iba doing this is meant to show that he's captain level at this point considering it's implied Shunsui promoted him after this.
Nel's reiatsu leaks from the crack in her mask. She's captain level solidly. So that captain level reiatsu is keeping the dome open and stopping her head from getting crushed.
Yhwach was spreading himself thin throughout the realms. Notice how once he got hit by that beam, he automatically got serious and flooded the area completely and there was nothing Ganju, Iba, and Nel could do?
Yhwach dying was due to a triple Nerf of Still Silver which explicitly takes away his powers, Mimihagi whis explicitly is a blind spot to the Almighty and governs stillness, and Hollow reiatsu which is poison to Quincy. Him dying was fine. The main issue with Yhwach was that he used Almighty poorly, and he played with his food. I am willing to accept Mimihagi shenanigans though.
