I meannnn I don’t exactly understand why people think Masaki deserved better since his a...

Tbh I kinda knew that Masaki was going to be the 2nd lead from the very beginning. He us the typical tsundere boyfriend who knows his love will be forever unrequited. But at least he was upfront about it and asked Uke out.
Meanwhile Kei kept on denying his feelings and at times took uke's feelings for granted ever since they were young.
A lot of people were rooting for uke and kei cause people thought he realized his feelings for uke later and wasn't aware about it until Uke left. But getting a girlfriend just even after knowing how uke felt was kinda the last straw for everyone who ever sympathized with Kei.

But like kei didn’t know the uke liked him? I mean it’s just a misunderstanding and both of them had relationships with other people. Ig I can see that masaki is very upfront about his feelings even though I don’t specifically like him

I understand and I complete respect your choice. It just that there are certain things which are kinda like a loopholes in this manga. Maybe because it was too rushed. Like how in initial chapters Kei was like even though I knew you loved me and then him reasoning with the fact that he was like a younger brother to him was a bit confusing. And I mean Uke's response to Kei's gf was the biggest sign of his doubts of uke's feelings.
Personally I don't like Kei because of his push and pull behavior. He says he tried to avoid him and let go. Yet after 2 years he is desperately trying to butt into uke's personal life.
The only flaw that I found with Masaki was that he was not being honest with his feelings at first but got cautious about it the moment there was a rival entry. And yes he is not given a lot of chance by the mangaka to show his feelings during the courses cause she already decided the mc. But I think his character would make the best second lead if he was given a lot more attention.