The thing about renewables is that almost all the cost is upfront. I have solar panels on my roof and they're going to keep producing energy at the same rate regardless of what the price is, because the marginal price of running them is basically zero. If places are installing them to meet carbon targets, that's also unaffected by price.
Also, oil and electricity aren't so much directly in competition with each other while the EV market remains small. Natural gas, yes, but that was already cheap.
Solar panel degradation is tiny nowadays. For monocrystalline cells the degradation rate is around 0.36% per year, which means in 10 years your panels will still be outputting about 96.5% of what they output brand new. Polycrystalline cells are around 0.64% degradation per year.
Solar generally comes with a warranty, in the range of 80% of nameplate capacity after 20-25 years. There is some degredation but at 20 years that is in line with utility replacement rates.
3.8kW of bog-standard polycrystalline cells, installed by a local company in less than a day. £5500, five years ago; I receive over £500 in feed-in-tarriffs every year. And this is at 56 degrees north.
(I never considered doing it myself - a dangerous hassle, and in any case the FIT scheme required an approved installer and a <4kW scheme. Storage or offgrid would be completely infeasible, it's too seasonal.)
Also, oil and electricity aren't so much directly in competition with each other while the EV market remains small. Natural gas, yes, but that was already cheap.