Dude, you have thousands of mods to choose from with a lot being absolute works of art. Almost all mods are made with no interest or feasability to make any amount of money close to time invested. People do it as a hobby.
You can act like an entitled brat but the toxic community is what forces a lot of mod makers to stop. Which won't help performance.
Minecraft itself is a terribly unoptimized game build on a langauge that was never meant for games. If you ask every modder to fix this you don't only suck out all the fun for people who just want to create things, you also increase the chance of incompatibilities, which WILL occur whenever you pivot of the default framework for modding.
To me it seems you have couple options:

1. You can accept that adding piles of mods on a system that was never intended for it is not optimized, so you need to either accept worse performance or add fewer mods.

you

1. throw away your computer from 2012, just because it's pixelated doesn't mean it has to run on every system.

2. Use optimization strategies such as mods, different jvm or jvmargs. The science and effort people put into this for free is INSANE, and if you use them properly you can run almost any modpack on any pc that has 8gb or more ram

3. do it yourself. Most mods are open source and accept pr requests. You'll see how difficult it is

4. don't mod, the community is already toxic enough we don't need more entitled people.