I think you don't understand these sites Stonehopper,
The other manga sites you say which have a bigger library are illegal because they make money off of hosting offical rips and scanlated manga. These sites are a buisness.
Mangadex on other hand is not a buisness, it only hosts scanlated and not official rips of manga. That said mangadex is also illegal as even scanlated mangas are illegal. Now because it only hosts scanlated mangas it often goes under the radar of publishers or the publishers just don't care about scanlations, also mangadex does not make any profit off of users supporting it in fact they often have to use their own money to support the site.
Now lastly why do think a free user should have the same experience as a user who supports the site irrelevant of the whether the site is profit or non profit.
Also having a pop-up that shows up once daily is barely an annoyance, it definitely doesn't make using this website a bad experience as you say.
as
@RogueKitsune already adressed the library stuff
lemme adress the popup/free tier user stuff
why do think a free user should have the same experience as a user who supports the site
i'm not claiming that, obviously a premium user should have perks, but nagware does not improve premium user experience, rather it just worsens free user experience. so unless the goal is to drive away free users then i don't see an excuse for nagware
Also having a pop-up that shows up once daily is barely an annoyance, it definitely doesn't make using this website a bad experience as you say
it is my personal opinion that it does worsen the user experience by a noticeable amount just like cookie prompts, i understand the necessity to prompt users for donations, but as i suggested there are better ways to approach it, and (as a reply to
@RogueKitsune ) if the concern are people that lack basic comprehension skills, then that does not justify locking the setting to premium only. i'd even accept a 3 choice setting: "resets daily (free user)" "always in navbar(free user)" "never show (premium user)"
i'd say that strikes a good balance between noobs, advanced user and premium user?