SS gear has a hiss noise floor too. A well designed & implemented tube preamp and tube power amp pairing should be dead quiet, even with ear up to drivers, on 96 dB speakers. I can’t speak to efficiencies beyond that. You’ll run into problems if you have a bad gain structure, for example tube line stages with gains 20dB and more can be a problem for efficient speakers, especially when run through high sensitivity amps - this is just too much active gain after the volume control, which acts as a gate for maintaining maximum signal to noise ratio from your upstream gear. You also have to be careful with tube selection in a line stage - for example, the 6SN7 is popular, but the sweet sounding 1940’s variants often tend to have issues with noise and microphonics, which will hurt your noise floor. Later 1950s/60s GTA and GTB versions tend to be a lot quieter. And of course, modern production tubes can be selected to be very quiet.
Tube phono stages shine when you pair a good tube MM stage with a SUT or a JFET MC stage. It’s hard to eliminate all audible hiss, but it should be way below the level of groove noise. Here, the efficiency of your speakers does not matter, because your phono stage’s signal to noise ratio is preserved by the downstream volume control.
When I hook up VAC power amp (16 tubes), Master preamp (2 tubes), Renaissance SE Phono & SUT (6 tubes), it’s an exceptionally quiet noise floor on my 96dB Tannoys.