Is it any different from selling TSLA, buying MSFT and triggering capital gains?

Legally no, at least in the US and NZ, but technically yes. On any stock exchange I know of, you'd sell your TSLA for cash, then use the cash to buy MSFT. On crypto exchanges there tend to be a lot of trading pairs with tokens on both sides, so cash is never involved.

not conceptually, though I don't know much about crytpo and have 2 questions:

1. can you recognize a capital loss on unregulated products like crypto and NFTs for favourable tax treatment?

2. do the exchanges (from an accounting perspective) trade directly between coins or move through a fiat (i.e. USD) currency?

So it might be more like "trading" stock directly without seeing the cash hit your account, which confuses people as to why they trigger a capital gain. The extra step of calculating the value of the source stock at the time of transaction is being missed.

> can you recognize a capital loss on unregulated products like crypto and NFTs for favourable tax treatment?

Depends on the country. The US and Canada allow it.

> do the exchanges (from an accounting perspective) trade directly between coins or move through a fiat (i.e. USD) currency?

Doesn't matter. If you swap TSLA for MSFT with someone there is still tax due.