So currently only a tiny amount of empty blocks are mined
A total of 71 empty blocks were mined in the first five months of 2020, accounting for 0.3% of the total blocks produced — less than half of the 0.79% figure from the same period last year source: https://www.theblockcrypto.com/post/67928/bitcoin-miners-are-mining-fewer-empty-blocks-in-2020-and-it-may-not-all-because-of-chance
I agree that it does not make sense from a game theoretic perspective for anyone to just mine empty blocks all the time (which would mean we would be close to 100% of empty blocks). As a miner you want to sell your btc in other blocks etc.
But I think a fair question to ask is why this number is so low. My intuition here is that the bitcoin mining race is extremely competitive. And anything that could give you some sort of advantage is always used.
If you just ignore txs you do not have to validate them and do not have to include them in one block and therefore can same some amount of time for mining the new block. This would be a competitive advantage over miners that include txs. Therefore I was surprised that the number of empty blocks is so low.