Yes, under a pro-spending, forward-looking government (such as the one we had from roughly 1997 to 2010), staffed public services improved and a trajectory was laid down for future improvements.
Under pro-austerity, myopic governments (such as the one we had from 2010 until now), public services have been rotting from the inside.
It's not difficult to draw a straight line from one to the other. Pouring money into "diversity" is certainly nothing to do with it, and that goes double for our current reigning party.
For what it's worth, it's a testament to the overall resilience of the NHS as a service that it has broadly managed to weather the storm of long-term underfunding and is likely going to continue on track until a forward-looking government is able to come back and breathe life back into it again. Roll on 2024.