What is the max number of transactions per second that Bitcoin can support?

Lightning scales infinitely.

There are people using Bitcoin as a currency, via lightning, right now. More join all the time. The network expands.

It is a currency, is used as a currency, as sats. It is also a long term store of value as Bitcoin. You can ignore reality as much as your like, but the world has moved on from your 2017 era complaints.

Ah yes, Lightning, the system where you have to establish an escrow fund between you and anyone you wish to pay. Sounds wildly practical.

that’s not how it works. You establish a channel with a network peer, spend some to add incoming liquidity to your channel, and reach the rest of the network. Send and receive payments. Yes the limitation is the liquidity and balance in your channels, but as far as routing goes we are all only a few hops away for each other.

It is wildly practical today, and there are several good custodial solutions if you do not wish to run a node yourself. Please give it a try!

A currency that requires you to run and a node and does not allow you to perform a transaction unless you have staked more currency than you are currently spending is not viable.

Especially when it's an assertion about the definition of a word.