That is, it comes with lots of advantages through being part of an ecosystem that people may already be part of or at least have some trust in because it is well known. Additionally it's already associated with helping people and projects in a way that may not be purely transactional, which fits how some people feel about their projects (thus the option to donate as discussed here).
Just because two models can be boiled down to essentially the same thing doesn't always mean they will perform equally as well. Sometimes the small distinctions and details are very important.
There's lots to unpack there that make it different than most other games I've played, but you can get a good idea from watching some Twitch streams.
It is almost a must if you're a casual player. It is too hard to keep up with the barters, flea market rates and even just the quests and items for quests.
I haven't played in a few weeks though, from a combination of the friend I usually play with being less interested (and not wanting to level/quest much without him) and being busier myself. That's sad, because it really is pretty amazing once you get the hang of it (I just stared at beginning of this wipe) and have someone to play with. Playing alone is fun too, but with one or two good friends is really something special.
I'm not sure I would consider what they do effective in banning trade bots (the captcha seems ridiculously easily beaten), I think the Found In Raid object flag is probably the really effective thing keeping most bot usage down, since it attacks the actual incentives of using a bot (it's still useful to auto-buy when markets dip or someone under lists an item, but that's about it I think, but I may be missing a use).
That said, if all you're doing is scanning the market results and not buying anything, it's probably much easier to not trigger any problems with the devs. The market data is really useful for those that like that sort of thing, but it's not really that much of an advantage, just a way for those into the economic portion of the game to go deeper.
I mention this because at the current moment, he has 4,757 patrons, and that $5/mo is the only official tier offered. That's $19k/mo, minus Patreon fees. This is the first time I've used a Patreon subscription to power a site account, which I wasn't aware could be done (I subscribe to a few web authors though, so I'm not new to Patreon). I think this is a really interesting way to provide gated site access, and it's fairly low fiction for a lot of people, because they either already use Patreon, or have at least heard of it so it's not some random site charging you or that you are paying. There's lots of benefits I see to this model, and I think if I have a project that fits it in the near future I'll try it myself. Maybe it's something that would work for you (you'd have to set the monthly price at something you think appropriate). $1 from 100 people would get you that $1000 in less than a year, and you might also get better targeted info on what features the people that are willing to pay think are more important.
I agree asking for donations doesn't work. I don't like donating like that. I am willing to allocate a bit of monthly money to people if I feel like I'm getting something worthwhile in return though (it's a limited amount, I try to keep total Patreon expenditure at or below ~$50/mo).