Never heard of this problem until now. Googled it and came up with 3 youtube videos on the subject so it seems to be a thing. Not sure I would go as far as saying that the system is "prone" to failure but it seems it can fail, hardly surprising, everything fails eventually. There was an issue raised by Lens Rental a year or so back where they found fractures where the sensor mounts onto the IBIS system on some Sony cameras. I think that is correct but Im working from memory here.
On the question about Sony having lens stabilisation, yes of course it does. Not sure which lenses exactly but my 90mm macro, 24-105, 70-200 and 200-600 all have lens stabilisation. When using a lens with stabilisation it is in fact impossible to use IBIS on its own, the system will not allow it. The IBIS and lens stabilisation works together in this case. I have two sigma lenses, 14-24 and 85 f1.4 and they work with IBIS only not being stabilised internally. The tiny Sony 28-60 kit lens is obviously also not stabilised. When using old manual lenses it is necessary to manually input the focal length of the lens into the IBIS system in order for it to work correctly. I do this with an old 500mm Minolta mirror lens and it has worked well except on one occasion when I accidentally entered 50mm instead on 500mm, nothing broke but it didn't stabilise effectively.
The stabilised bodies I am currently using are the A9 and the A7C. I have also owned the A7Rii, A7Riii and A6500. Never had a problem in about 4 years of busy commercial use.
I don't know how prevalent IBIS failure is with Sony, above is simply my experience and also some information on how Sony has implemented stabilisation regarding conjecture that Sony lenses do not have stabilisation and all stabilisation is done using IBIS.