There are a lot of cars sitting around more, as people work from home. Batteries go dead, as there are a lot of ongoing drains with modern car electronics. Something is energized all the time so that keyless entry system will work, for example. Those dead car batteries have to be replaced.
To keep this from being you, buy a modern electronic float charger and hook it up. I have on the wife’s car and a motorcycle I have.
I drove a scion FR-S 150 miles round trip every day to work until work from home. I bought it new in 2013 and put 195k miles on it. Since April 1st (WFH began), I’ve put less than 50 on it. I’ve also learned that the battery will go a month without being hooked up. Meanwhile, my 2004 Z71 silverado will go dead after a week.
Take the vehicles for a ride of several miles every few days.