Ankle weights make the abs BURN during low boat variations and other ab exercises where you use legs. Flutters or leg raises will not feel the same let me tell you hahaha. I would definitely recommend. Another great addition could be resistance bands for leg and glute exercises. There are some cheaper ones out there that work amazing, and If you get a set, you can combine different heaviness by stacking them.
Dumbbells are awesome but they can be pricey. That are SUPER versatile but you will achieve similar results by getting your ankle weights on your wrists. If you are interested in them I'd get a lighter set (1~2kgs or so) since you can combine them with wrist weights. Or maybe get the adaptable ones. They are pricey but you can change the weight on them based on your needs which can be a good investment long term.

I've actually been eyeing a pair of ankle weights on Amazon for the last few weeks. I think I'll be joining you in trying them out. Haha

I have 5 pounds and honestly I wish I would have started with the 2 or 3 pounders because it is definitely a work out I tried walking a mile in them and my legs were like jelly at the end 🙃 😅 I would not recommend doing that BTW unless you have some crazy strong legs and stamina. But I think like some 2 pounders doing that would be pretty good. But they definitely give a great workout for booty days for like donkey kicks, leg pulses and workouts like that. I'm at home workout equipment fanatic so I think everything is useful 😅

You definitely feel your muscles working when you use them. I didn’t use them for a long period so I can’t say for sure but they do make a difference