Bingo! No system is perfect:
https://en.wikipedia.org/wiki/Arrow%27s_impossibility_theore...
They all have some advantages and disadvantages.
Weak coalition governments like Italy has had in much of recent history are what you can end up with with purely proportional voting, and they have some serious problems of their own.
I think FPTP with a STV type of system is nice - you can still vote for who you want to, without having to vote tactically, but there's still going to be a stronger result.
Whether you think that is a reasonable goal is a case of personal perspective imo. I dislike the position that implies FPTP is a flat out inferior system rather than one which has some advantages and some disadvantages (as do all other systems).