- Edited
DeletedUser84 Thanks for your kind words!
I think all SIMs have a phone number anyway, even if it doesn't actually work in the traditional sense. The silent.link data only SIMs do - it is mentioned in their FAQ - and I've seen 5G data only SIMs used in 5G home routers with numbers too. There's also this admittedly rather old stackexchange post saying the same.
It probably makes little difference in practice if you don't plan to give the number out anyway.
If you can get a better price on a SIM with calls+text+data and just not use the calls+text compared to specifically buying a data-only SIM, that is probably just as good from a privacy point of view and obviously a win financially. Depending on your precise threat model, having a SIM capable of calls+text as well just might come in handy in some kind of emergency (I need to call X right now and mobile data isn't working), even if you plan never to use it.
(The "practical guide for the paranoid" I linked to does say there may be a reduction in attack surface from not having calls or texts, but that it doesn't particularly matter otherwise.)