the anon's comment makes me very sad in a specific way in a fannish context because i feel like they're missing the entire point of fandom which is to be creative together. not only can all of those things be done by a person, but i promise you there is a person out there who would love to do those things for you!
one of the great joys of fandom is being involved in someone else's creative process. whether it's through betaing, just chatting about ideas, making an insightful comment on their fic, etc., it is so fun for both people involved when a creator has someone else to "yes and" with or to have "omg!!!" reactions or to say "i'm not sure that works, let's workshop that."
one of the main reasons that many people write fanfic even though we're not getting paid and it takes time that could be spent on other things is that the process of writing in community is so rewarding and fun. imo the most obvious way that it can be rewarding and fun is through comments once you've posted something. but having someone hold your hand while you create something is a close second. (and i'm sure for some people it's number one!)
i have made some of the best friends of my life through creating together. i've had some of the most fun i've ever had in fandom getting high on mutual love for a fandom/character/ship/whatever through betaing or being betaed.
don't rob yourself or someone else of that experience by using a soulless, carbon-burning plagiarization machine to do something that a person would love to do.
that said, i know that, especially if you're new to fandom, it can be difficult to know where to start in finding someone who will beta for you.
here are a few ways to go about it:
put out a post in the tag of whatever your fandom/ship/whatever is asking if anyone is willing to beta. ask people to reblog it if you feel comfortable doing it. if it doesn't work the first time, try again a few weeks later--timing may have made people miss it.
after you've made a few friends in fandom, ask them to beta for you.
leave some really good comments on the fic of a writer you admire. build a rapport. once you have, ask if they ever beta for anyone. if they say yes, ask if they will be willing to beta for you.
look at the author's notes on fics you like. see if the writer mentions their beta. if they do, after leaving a good comment on their fic, ask if their beta is ever open to betaing for other people.
as long as you aren't entitled about how you ask, it is okay to ask outright if someone will beta for you. but don't do it out of the blue on someone's fic if you haven't also commented on that fic! that's just rude!
after you've complimented the writer, ask if they ever beta. something like: "i loved this fic so much for these reasons: [reasons]. your writing is so great! do you ever beta?"
if they confirm that they do, follow up with: "do you have the time/energy/interest in betaing something for me?" protip: it helps if you tell them how long it is, what the pairing is or if it's gen, that sort of thing. some people might have the capacity to beta for a 2k word fic of their otp but not for a plotty, multichapter fic.
the worst that can happen is that they say no, and i promise that 98% of people who say no will say it in a kind way. people are not going to be offended that you asked. they're going to be flattered, even if they don't want to or can't say yes right now. and even if they say no, they might have a suggestion of someone else to ask!
and remember: fandom is reciprocal! that's the entire dynamic! so if you use a beta, you should probably beta for someone else at some point in time. it doesn't have to be right away, it doesn't have to be for the person who betas for you. maybe you're just starting to write and don't feel like you have the skills to beta well. maybe you're really busy with life right now and don't have the bandwidth to beta for someone else. but at some point in your life, you will feel more confident and you will have a bit more time, and when that happens, be the beta you want to see in the world! i swear that it's fun!
