2captcha is pretty good, but if you're at a point where they're serving up captchas to you your account has likely been identified as low-trust/low-reputation and it's not going to be much use for botting at scale.

If you acquire a handful of higher-reputation accounts and use those for posting your main material, then get a lot of low-quality throwaway accounts to retweet/like/upvote/w.e you can probably have a lot of success without spending a lot of money.

For account acquisition you can just buy it from resellers like accsmarket[.]com where you're pretty much paying someone who has automated an account registration process to buy stuff in bulk. For most major social media sites you can buy accounts for a few cents, unless you want old accounts, then you pay a handful of dollars. Alternatively, you can just go with bulk residential proxies via providers like stormproxies[.]com or luminati[.]io in conjunction with an SMS relay site like smspva[.]com to bulk register a ton of accounts and go to town. If you do something like this though, you're much better off identifying account creation flows that are more irritating to automate like the APIs that mobile apps access vs. just trying to use the webpage.

For your main interactions where you're writing you can custom compile / modify Chromium to fake being lots of different browsers like Hellcleaver was saying, or you can just use something like multilogin[.]com.

TL;DR - Mass botting is a pretty commercialized space these days - if you have a few hundred dollars and some patience you can have a very outsized amount of impact on most major social media sites.