GTO and polar orbits can still land, they just use the barge ("Autonomous Spaceport Drone Ship") instead of returning to the launch site.
There are launches which don't have enough margin to land at all. The upcoming EchoStar 23 launch is one of these. This is a GTO launch of a really heavy satellite, so getting it up there requires using the fuel the rocket would need to land.
However, this is rare, and it's likely that this will only happen a few more times at most
I think the key point there is that SpaceX can offer many new options for launch that seriously expand the kinds of contracts they can accept.
If your payload and destination allow for reuse then the cost of your launch is (cost of the whole rocket) / (number of reuses) + (landing & refurbishing costs)
If you require the full fuel of a Falcon 9 it might make sense to accept higher risk and launch on a rocket that is at it's last launch.
If you also don't want that risk, then maybe a mid-life Falcon Heavy can be cheap enough for you.
If Falcon Heavy is still too expensive even with re-use then maybe a one shot Falcon 9 is right for you.
There are launches which don't have enough margin to land at all. The upcoming EchoStar 23 launch is one of these. This is a GTO launch of a really heavy satellite, so getting it up there requires using the fuel the rocket would need to land.
However, this is rare, and it's likely that this will only happen a few more times at most