I would say No but what do you think

If you're the kind of person that will stand in front of your own or a friend's locker to chat, then yes, it may be a cause to being late that's your fault, not the existence of lockers. ( Not to you specifically so don't take it personally. :) )

No, unless someone has to go far out of their way to get to their locker to go to their next class.... then it would be.

But for me, I think bathroom breaks are more of a cause of being late. Teachers dont let you leave in the middle of class to go... so in between classes is my only opportunity. By the time you get your books and stuff for your next class, go to the bathroom, and then finally get to class, your 5 minutes is long gone. It takes me at least 2-3 to go to the bathroom. Ahhh 5 minutes isnt enough.

Yes I agree with you.

they can be... Like, lockers can get jammed, your things may fall out and you have to stuff it all back in, and it can be really hard to get to your locker when people always stand in front of them This year I don't have time to go to my locker. I don't even know where it is, or my combination. Most people in high school don't use theirs.

maybe sometimes in middle school when you actually need to use your lockers in between classes, or during the first week of school when you can't remember your locker combination but...
generally speaking, at my hs at least, everybody just carries their bags/books around with them. we use our lockers like once a year.