The first to start was yes to the Bundesliga but in this case, you don't have to look at the timing but the numbers.
Germany became infected after Italy but official numbers, although doubtful, say that at the time of football played Germany had only about 20,000 positive cases.
To date in Italy, there are still about 40,000 positive cases with an average of about 2000 less positive per day in the last week, it is hoped that for the beginning of football there will be only 20k of cases or less.
- To reduce impacts (delay) on the start day of the new season.
- To avoid any bad impacts on the second wave of infections when the whole nation will be resumed and back to work after the lockdown.
I guess the La Liga want to hurry up and finish their season winthin one month is for the same reason. There are pros and cons but the common things are leagues will be finished after all (at least people try to finish it).