I work out at home with dumbells, the one thing I miss vs a gym is some way to do lat pull downs. I can’t do a chin up and don’t feel like I’ve got a good way to work up to it.

I also don’t work legs super seriously, I have 2x75lb dumbells I use for squats and deadlifts, I could do more if I had heavier weights but that’s not a priority.

If you haven't tried single leg movements, that's the way to increase load on your legs when you don't have more weight available.

Moving fast is also a good way to increase intensity without increasing weight (you can clean less than you can deadlift, for example). The training effect is slightly different, but probably more useful for the average person tbh.

For progressing to a chin-up or pullup, have you tried negatives? Or rubber band assist? Or, if you are willing to get rings, you can lower them so some of your weight is supported by your feet on the ground (body straight like a plank), changing the height of the rings will increase or decrease effort.

Chin up progression is eccentrics and band assists. They'll get you to your first chin up faster than lat pulldowns since you're actually doing the movement.