Here you get 20GB for 20 euro on prepaid with unlimited calling (which I never use at all - all my calls are on Whatsapp etc :') ). Or 5GB for 10 euro. I use the 20 euro plan as my 4G backup for when my fibre goes down and I worked a whole week off the 20GB during the first lockdown when there was such an issue (I do shut down some stuff like steam downloads and netflix with a script on my router when it's on failover). It really saved my bacon. The good thing about it is that it's even prepaid so I can just load money up on it when I need it.
Strange thing is, we have 3 mobile operators here too (not counting the many MVNOs). Shouldn't be a barrier to decent competition. If you have more than 3 the available radio spectrum starts getting diluted anyway.