Mempool evicts tx based on fee. So there is no “infinite” pool. That’s some weird concept dude.
Where the hell are you getting your BU numbers?
BU is both unbounded and unsafe / with random chain splits every time the network switches, and users forced to follow miner “offline” collusion to make protocol changes.
Chain size can be 30TB with BU, not 1TB. And worse, the bandwidth required to run a listening node could be 20mbit or more… well beyond the ability for all but the largest exchanges and miners to run.
So under that scenario, bitcoin is essentially dead.