Bitcoin is the one that limits subnets while Monero does not really have good protections against this except for the ban list which seems to be getting circumvented.

If there's spam attacks or large adoption increase post FCMP upgrade then node resources requirements will stop a lot of people from running nodes. It could be more akin to Ethereum nodes.

Monero Txs are 50x the size iirc, and require more compute. so I think the total on chain Txs will be similar to Bitcoin at the cost of being more resource intensive

Monero devs don't really value node costs being low (measure of decentralization)