Swim

I've never had an Apple Watch but have rarely had issues with multiple generations of Garmin's (started with the Swim 1 back in 2012). The trick to good lap counts is a strong push off from the wall (you don't need to flip turn) and swimming consistently during the lap. Mixing strokes during a lap, stopping, turning around before the wall etcetera can mess your count up.

Garmin swim 2 is what I use, had the Garmin swim 1 before it

If you can find them on eBay the original Garmin Swim is still a solid watch for recording pool swimming. I would still be using mine but I failed to close the battery compartment tightly after a battery change and it died with water ingress. Currently using a Swim 2, which as a plus has wrist HR, but is slight harder to read in the middle of a session (and the displayed lengths count lags behind what you've actually swum, although it catches up if you click stop). It has a small form on your wrist, so it doesn't catch the lane rope. I like it.

pretty happy with garmin - stroke detection is pretty meh but that only matters if you need it. otherwise doesnt seem to affect laps and therefore distance, would say its 95% accurate as long as you manually stop the set so it doesnt trigger at the wall when you are fumbling with your cap and goggles.

just leave it at the wall if you are not going to stop. flipturns tend to trigger the lap pretty well, a good hard push is even better. only do the lap button when you complete your set and going to be stopped at the walk for a rest.

I have limited experience with both. Garmin (Swim) was not as good as AW for counting laps without flip turns. I killed an AW by swimming in a saltwater pool though.

Use a watch to track your swims. I can only speak on pool because that’s where I swim. I use a Garmin swim watch and track my workouts on a 25 yd swim. It automatically tracks your HR and pace. On some rare cases like kicking with a kickboard and alternating arms (butterfly), it doesn’t track my swim so I manually have to use my watch to track the “drills section”.

I love my Garmin Swim watch! https://www.garmin.com/en-CA/p/665374/