I would say it depends on what you use the data for. Generally wearables of all brands are not that accurate but also for The general population they don't really need to be. i have found that they twll you what you already know. if you wake up wrecked and have had a pint or two the night before your sleep score will be poor. but you already know that because you are tired. Friends use Whoop and like it but they are dog expensive. Whoop, Stryd, Coros have all disrupted the market the same way garmin did to polar 20 years ago i use HR a lot but don't consider it essential, in fact wrist HR is also fairly inaccurate for all bit steady state running or cycling. Absolutely worthless swimming. HRV can be useful but you're better off spot checking it with HRV pro and really it tells you if you have been overdoing it which unless you're an elite or doing very high volume it of limited use. it is nice to see things like estimated VO2 improve with training but again not worth anything except to give an indication of improvement which you will get from times and distance and percieved. another friend uses as apple watch and they seem to be aimed at general health rather than sport. So basically I'd say they are all good but only if you're into data etc and certainly far from essential. FWIW i use a Garmin forerunner 245 with a garmin HRM pro + chest strap, its great. worth the upgrade from my old Garmin 55 which was grand too but the battery died.
Good stuff El-G, just to add to that - I have an Apple watch, its my 3rd one over the years, they have improved a lot from where they started but i would still class it as more of a general fitness watch than the dedicated Garmins. Having said that the Apple watch gives me everything i need so it tracks your general day to day movement etc so you get a sense of how sedate you've been! I dont bother with any of their basic metrics where it measures steps and standing hours etc, completely pointless stuff.
For tracking training/racing etc I find it very good for running, you can set the screen to tell you as much or as little feedback as you want. I have it set to fairly simple metrics as all I want while running is the distance and a sense of my average and current pace, and HR. When you are done running will give you a load of additional feedback, splits, zones etc etc
Its shit for swimming, constantly pauses during pool swims and I've found the GPS losing chunks of sea swims.. really annoying and not much use
Its great for cycling though, will give you your current speed, distance covered, climbing etc etc, and like running there are loads of stats on the phone when you are finished. I haven't found myself trusting the multi-event setting on it yet for triathlons etc which invariably means me forgetting to restart my watch at some stage and recording none of them properly. I think you should be able to tip the watch as you enter and leave transitions manually which would put my mind at ease, Id guess the Garmin's do this better
The Apple watch pairs with an iPhone seamlessly as you would expect and links to Strava no problem. i do find the read outs from the same run or cycle vary a bit despite the measuring device being the watch for both apps.. haven't quite figured that one out yet
Having said that a friend has a new Garmin and the think is forever annoying him with shite you already know, id have it all disabled if i owned one as I dont need to be told I am tired, happy, ready to train etc