I like how TextNow.com provides a physical Sim card for a one-time fee of $5 and no ongoing costs for calls and texts. They are funded through ads and give you a new number if you go a week without a call or text. Without requiring KYC docs, they're providing ephemeral phone numbers for intermittent use and permanent ones for regular use. Both have their use cases and it's very nice to have a free and anonymous number. I hate monthly bills and can easily ignore their ads. 

 silent.link is great but last I heard the number they give is only to receive calls and texts, not to make. Great for privacy though.