There has always been faucets giving coins and the only complains I've seen so far have been from people who want large amounts and the worst part is that I have not seen any reasonable arguments for needing such amounts as opposed to using something like regtest.
So I wouldn't say "it is not easy to obtain testnet coins".

What the future holds?
This attack is not going to change anything, after all this is not the first time testnet is under a miners' attack.
But if the trades continue and testnet coins start gaining a value and scams form around it, we can see testnet3 having the same fate as its predecessors and we may enter testnet4 era.
Although if we do, I think we should come up with better mining rules that are not complicated like signet and not as vulnerable like testnet3.