It's meaningful because charts showing "primary energy" include waste heat, so you only need to replace ~1/3 of primary energy with renewables to fully replace its use.
what charts are using primary energy? the only useful metric is energy we can actually use, and all statistics I know generally compare emissions per kWh of electricity, not primary energy.
We don't take inti account the energy of the sun for calculating solar energy either.
The ones I've seen people using in online discourse are these which mislead the heck out of people trying to figure out how much work is needed for displacing fossil fuels.
If we did then solar energy would be the most ridiculously inefficient energy source on Earth. Only 0.000000045% of the Sun's energy even hits Earth at all.
Though now that I think of it, uranium comes from supernovae and neutron star mergers. So nuclear power might be even less efficient.
If you look around, there are tons of people who claim that all of the primary energy used today needs to be provided by renewables in the future (and that that's impossible).
It looks also like this graph is completely ignoring the fact that the excess heat is actually used to heat up homes (at least in Finland), making the process of burning coal way more efficient.
That said, renewables are obviously still better on the climate, and should be heavily invested to.