At issue is that something is going to grow if you add light and fish waste.
The management issue is that we have a choice of what will grow.

So..........if you only add a one little old plant to a tank and expect things to do well and add too much light to the rest of the tank, probably not.

Something is going to grow and with lower plant biomass and coverage, it'll be algae. They only want a few plants, they need to reduce the light if they are getting a lot of algae.

Light, then CO2, then nutrients.
PO4 is not a bad method without any plants to limit algae, or low NO3, etc.
It's tough if you have fish etc...........they release it all the time.
Just enough for the algae to get by ..........if you have enough light.

So throttling light down is a good solution.
Of course many cannot or will not do that also..........

Regards,
Tom Barr