Biden is the most popular president ever, millions of votes more than Obama.
It comes down to a few ten thousands (or less) in critical swing states.
There's a compelling statistical argument to be made that states like Georgia, or maybe perhaps even bigger margin in FL, might have gone another way without laws & regulations to make it harder to vote and cast a ballot by mail.
My point wasn't about "who won", only pointing out the statistics of popularity, considering that an election is basically a popularity contest.
The most unpopular president (and vice-president) got more historical more votes than the last most popular president of the past 50-100 years.
You need to show papers to go grocery shopping: that's OK. You need to show papers to vote: that's not OK.
Do you see the inconsistency?
The vaccine-card equivalent of Republican Voter ID requirements would be mandating that everyone present a vaccine card before being allowed to vote with the intent of discouraging eligible Republican voters.
The equivalent of present-day pollbooth security in vaccine-card form would be requiring people to associate themselves with an official vaccine record before shopping / working / etc. You wouldn't have to present an ID on the spot, but the records would be checked to look for two people claiming the same vaccination record, someone trying to claim a record that didn't exist, etc. Discrepancies would be investigated and if you were found to have fraudulently represented your vaccination status you'd be in trouble.
That is to say, one major difference is the availability of the papers.