It's interesting that you say that Biden voters feel disrespected because Trump voters protested something in the way they did. When BLM protesters vandalized (mostly poor or middle-class people's) shops, do you think it was reasonable for non-BLM people (most Trump supporters) to be outraged? If not, therein lies the problem.
BTW, there were violent riots when Trump was elected president, including in Oakland, Portland etc.:
https://en.wikipedia.org/wiki/2016_Oakland_riots https://en.wikipedia.org/wiki/2016_Portland,_Oregon_riots
Mail dumping, interception and modification of ballots, just plain errors in ballots or failure to mail them (these last two are not in the 'game the ballot' category, but they do happen with mail-in balloting) all occur in almost every election. Even if they do not materially change election results, they affect the perception of the legitimacy of results. The perception is as important as the reality of the process. Any law that helps improve the perception should be welcomed.
Did any of this actually happen?
> ...they do not materially change election results...
So... what’s the problem again?
I would bet Federal bureaucracy would have hampered say a Clinton response, but Trump refused to lead, take even the most basic federal action, and he basically doesn't care beyond testing numbers affecting his election. He specifically withheld supplies and support to D states until 'they have to treat us well' e.g. be a sycophant on tv.
Maybe voters would have confidence in mail-in-voting if Republicans & Trump didn't spend a year attacking it and spreading politically motivated lies.
VBM is secure and many studies have shown there is very very little fraud.
My state Colorado has been sending ballots to almost every voter for years and it works. A Republican SOS helped craft and refine the system.
used by like something 94% of our voters, clearly trusted and used widely on both sides. Notice it doesn't get attacked by legitimate Republicans here
https://www.5280.com/2020/05/no-fraud-isnt-rampant-in-colora...
Republicans have been ruthlessly effective here and there are plenty of laws that are passed under the guise of 'anti-fraud' but really are to suppress the vote usually in favor of southern Republicans. Copy of license, very very restrictive rules on who can request a ballot, reducing drop off locations etc Same playbook for a century, different rules
I strongly suggest you stop and think for a bit about what this means.