In an ideal world, yes, but it doesnt work for everyone. If you can't use power on every ride then a lot of the data is meaningless.
With a powertap, I cant use it on my mtb/cross rides in the winter and I use my race wheels for racing so it misses out a large chunk of my riding. That puts the TSS and freshness graphs out, particularly if you race a lot and most of the summer is spent in a race/recover cycle. It's also going to miss some of the max power, ftp, etc stuff as well.
I'm sure you'd still get some useful data from it but there's also a lot of guesswork involved to fill in the gaps too.
TP can utilise your HR for freshness stuff to some extent I found, yes it's not ideal when racing CX every week, but with a bit of common sense and good data collection the rest of the time I can get a good judge of where I am, also tracking HR from that dirty running exercise for overall fatigue.
I'm generally recording power all the time where possible. Just be nice to be able to have power meters on everything (will be the case in 5 years I suspect)