When I used to change oil myself, I never replaced a drainplug or washer. I didn't know that was a thing. I never had a leak.
Until recently, my cousin never replaced a drainplug nor crush washer. He never had a leak.
However, thanks to BITOG handwringing advice, Gold Plug, Honda, and Hyundai instructions; in our last 3 oil changes we did replace crush washers. Why? Just because all the alarmist talk and instructions convinced me we should conform to that widespread policy.
Does the crushwasher really need replacing? If it's noticeably crushed, scarred, or damaged; then it's probably a good idea and is cheap insurance. However, if it's not looking signifigantly beatup, then it's fine to reuse it, IME.
Same with oil plug bolt. If it's starting to get rounded bolt head or threads look bad, then replace it. If it looks OK, reuse it.
Don't overtighten drain plug bolt. A little snug is good. Tight is bad. Tight can damage things.
Don't overtighten the oil filter. Hand tight is good. You don't need (or want) to use a wrench to tighten it.