^During the job, I wrap them up to keep them fresh for next time.
It is difficult to wash them out thoroughly and washes paint into the drainage system which is not consequence free for the environment. White spirit to wash out oil based paints should not be washed down the drains at all.
During the last DIY project we had, compared to the amount of builder's waste and rubble produced, paint brushes will have scored less than 1% of waste produced^
^ This. We decorate about once every five years, if that. It doesn't take seconds to clean a brush, you can be there for ages rinsing and soaking and washing paint into the drains^ using gallons of water in the process and the brush still isn't clean. And that's just water based paint.
I gave up washing paint brushes out when I worked out that the turps I'd used to ineffectively clean a brush had cost more than the brush I'd tried and failed to clean and we don't buy particularly cheap brushes, just look for decent ones on offer.
Life's too short and in the great scheme of things, a couple of paint brushes and rollers every five years is absolutely nothing, even for an otherwise low consumption household like ours and I hope that none of the people criticising the OP are those types who wash clothes and towels after one wear/use, bleach toilets every day, use shower gel and shampoo etc by the gallon etc etc.