Why isn’t my car starting properly?

I have a 2008 Honda Civic Coupe EX-L which has served me quite well the past 5 years. This past year though it’s had an ongoing issue where the car won’t fully start right away. It’ll crank a few times, and then fail. If I try starting it again right away it’ll do the same thing. Eventually though it’ll start if I leave it for awhile so it’s not overly consistent, and it doesn’t do it every time I drive.

I’ve brought it into the mechanic multiple times, one time having my battery replaced and then the other two times replacing the alternator (the first one was faulty.) This problem has always come back though and just makes driving overly stressful in case my car decides to just not start again.

I’ll be bringing it to the mechanic again, but any input would be appreciated just so I can get a better understanding of what could potentially be going on.