I typically use 5sim(no affiliation) for phone number verification, although the phone numbers don’t persist so 2fa and otp doesn’t work with it, which is required for some services like Hotstar.
I personally used Telnyx, which usually isn't detected as "VoIP" because they offer actual SIMs with these numbers, usually for IoT applications. Sometimes they are still detected though, which annoys me a lot because usually the services that bother to do that detection are the ones I least want to have my phone number (ex: OpenAI)
I've resorted to hawking sites like BugMeNot and using the trash/spam accounts there, which usually manage to have some phone number or have performed some sort of weird exploit to get into their system somehow. It's how I managed to play quite a bit with ChatGPT around the tail end of 2022 when it first came out, but these days the rate limits are so strict that I can't ever get a single message through any of the shared/trash accounts (which is probably their objective).
