My fonts look bad
 

Hey! I'm new to Linux, and it looks interesting and fun, but there is one thing that bothers me a lot. Some fonts look like it's Windows with font quality settings disabled. I'm not sure what to do with it. Some fonts look okay, others feel like they are partially pixelated.
I've changed Fedora to Linux Mint because of this (I hoped it's going to fix itself with a clean install). But it didn't.
I've tried:
Changing antialiasing settings
Installing Microsoft fonts
Changing fonts in settings
This problem persists not only in browsers (I tried both Chrome and Firefox), but in Discord and Spotify as well, for example.
In the photo I posted, you can take a look at song names on the right panel, and on the current song's and artist's name. I'm not sure if you will be able to see it, because when the image is compressed, it looks differently.
Thank you!

Could you maybe post or link to a screenshot illustrating the issue? I think that would help clarify the issue at hand.

The dialog for attaching a file appears when you click the "Go Advanced" button beneath the compose/edit post window, but what I don't know is whether you have to have a certain number of posts before you can attach a file.

Thanks! Just uploaded more. Also, here are similar screenshots on Windows for comparison.