Virtual particles and related effects are actually widely accepted and experimentally proven (at least partially). Current physics wouldn't really work without them, or at least something that looks the same.

https://en.wikipedia.org/wiki/Casimir_effect

https://en.wikipedia.org/wiki/Zero-point_energy

https://en.wikipedia.org/wiki/Virtual_particle

https://en.wikipedia.org/wiki/Hawking_radiation

The gist of it is, that quantum mechanics prevents vacuum from really being empty. Any finite-size system or any system with some kind of influence/force/anything will have a lowest energy state that is not actually zero energy but slightly above. Which means that this non-zero can fluctuate and on occasion pair-produce and pair-annihilate particles (probability inversely depending on pair energy).

And yes, this sounds like some kind of ether...

You're probably thinking of the de Broglie-Bohm pilot wave theory, where there are actual particles with determinate trajectories at all times, which are probabilistically guided by a wave. I think they main problem with this idea is that it can't be made relativistically invariant, and so it can only be used for systems with low realtive velocities of its components.

OTOH de Broglie for one of the central ideas in the development of quantum mechanics: he inverted Einstein's idea about photons, which were previously thought to be waves but Einstein showed how they came in particle-like quanta. de Broglie realised you could apply the same thinking to matter, which had previously been thought of as particles, and describe them using waves. Subsequent observation of wavelike dynamics (diffraction) of electrons in the Davisson-Germer experiment got de Broglie the Nobel prize.