There is no reason to question Cardano TPS. Haters say no one uses the network….so the current TPS is sufficient. When the network is full, it won’t cost anyone ADA. This is a non issue.

Testnet they already did 250 TPS. And that’s not the limit, it’s just what they decided to stop at and said basically it can be whatever you need it to be, but if you set blocksize limit too high, tx fees too low, you could invite DDOS attacks and bloat the network until no normal users can have a copy of the blockchain, which would be a big blow to decentralization.