Usually problems with virtual numbers arise if you have not used them for a while. It may often come as a surprise to you that such a number stops working. You just need to take into account that those organizations that sell such numbers may be too unreliable and may either go bankrupt or simply disappear along with your numbers. A physical SIM card is much more reliable, but there are usually problems with anonymity when purchasing it. And the official seller requires verification of the buyer’s identity.
This is of course inconvenient. But this is much more reliable than virtual phone numbers.
Do not use your number to sign up and receive important log in codes, those who are a victim to sim swap don't know that it's from the network officers themselves, those who are smart knows that this is true, hungry monkeys are working in those sim cards company, do not trust any.
Also, I think it's stupid to leave your money on any gambling platform either big or small, because once in a while casinos can get hacked too and to my own knowledge about online casinos they do have poor security compare to crypto exchanges.
This is in case you really want to maintain anonymity as much as possible. Another question is how to find people who will buy these same Sim cards in office in their name. And then they will simply hand it over to you. But this is just a question that can also be dealt with specifically based on the situation in a particular country or in a particular area. But in any case, this can be done, although of course you will have to pay some money for this to the person who bought you the Sim card.
But it seems to me that this is the best way to maintain anonymity simply because more and more services require confirmation via SMS. And now it’s often not enough just to have some kind of email address.