I do not wanna come off as high on a horse or anything, but none of the replies even define what a good proxy is.
I have done my fair share of multi accounting and was sometimes paid to try and sometimes did it out of own curiousity, from small scales
Where and how do you check the quality?
Which protocol? How to make sure to not leak an IP? Does the provider clean their headers for http proxies, hows connectivity quality and do they rotate IPs mid session on non mobile proxies despite the promises? For this kind of stuff you need various testing tools, including a bot.
If mobile proxy + mobile emulator, you will get but be banned pretty quickly, been there, preciselly on TikTok.
Residential proxy, matter of time before you get assigned an IP that has been seen on the platform on another user or an IP which is blacklisted.
Static ISP? Many, many of their ASNs are known to Google and Cloudflare and the social media platforms.
Proxy selection is not easy unless you know preciselly to test them, which takes time and understanding.
The best proxy you could ever have is hosting your own where you can spoof the whole data packets at the router layer, but that is prohibitevelly expensive and pretty complicated, so you have to work with whats out there, the plug and play providers, theres less than a handful which cleans their pools and which can acquire new proxies faster than their pools get burned.