Honestly, the best fish finder is have a friend who really knows where the fish are. I am not joking: I have been fortunate to have known a person who taught me where to look, what to look for and more importantly when to look. At that time he used Loran and an ancient sounder.
I understand your confusion, I have been looking myself at upgrading one of my units. For me definitely CHIRP, Downscan and transom mount transducer. Although some features like forward scan and side scan would be nice I can't justify all the expense for the amount of fishing I do. I can be happy just catching sea robins!
I also advise caution when looking at the Best of 2019 product sites. I will check them out to get leads but then do all the research I can find from fishing/boating forums, sometimes even Amazon. It is amazing how different the reviews can be.
Support is important and the Best sites don't really address that. The user friendliness of the equipment is important too. It helps to actually play with the units at shows and marine stores if possible. I still after many years have problems making config changes on my boat that has both Garmin and Lowrance plotters/fishfinders. I forget how to do things and some units are a lot more intuitive than others.
No mater what you select, todays equipment is so far advanced from just a few years ago and whatever you go with will be wonderful