Very poor Open water GPS quality

Well, I don't think that the Sony's chipset in the grand scheme of the watch price is much more price-wise.

https://www.sony.com/en/SonyInfo/News/Press/202008/20-069E/

I think it would just need for Garmin to use that and implement support. Add some GPS settings to use dual channel or not and that's it :) 

How is this a good track?

If I'm running tempo or intervals and relying on the stats from that track (pace/distance) the workout is simply ruined. 

So lets hope that this new Sony Chip is used on the Fenix 7 and that it makes enough of a difference to resolve all our swimming issues

I have been having the same issue.  My swim track has been very erratic. It hasn't been like that in the past.  It is frustrating.  It seems hit an miss too.  I have had swims where the track and pace make sense and then others that look like the examples you shared.  My tracking in all other sports is very good. I just tried changing to recording every second, but I'm not thrilled with that because the files will probably be huge.