Why NOT TO BUY a very lightweight/ultra-compact stroller for rough terrain or for day-to-day use
TL;DR: The main priority for ultra-compact strollers is foldability. Everything else is subject to that - starting with sturdiness and space for the kid. They are meant for traveling and occasional use and may get damaged over time.
I often stumble upon this kind of situation: A mom unhappy with her bulky stroller (system) decides to move on. At that moment, her thinking becomes exactly the opposite of the one done when choosing the first pram. Meaning she (you!) starts to look for the smallest pushchair/buggy model possible. Eventually, she will end up looking at ultra-compacts, those truly small, foldable travel strollers that (folded) fit even an overhead compartment of a plane.
I know it seems like a good idea, especially after something heavy and robust. However, you should be aware of these facts before thinking like this. A very compact stroller is designed with FIRSTLY AND FOREMOSTLY the smallest fold possible in mind. All the other aspects and features of the stroller are subject to this need and will be significantly diminished. The frame won't be so sturdy anymore (it has to be thinner, the tubes); the wheels have to be smaller; the seat (much) narrower and often overall less spacious; the basket, of course, as tiny as it gets... Even if the frame is of higher quality (e.g., of a very good brand), a small stroller will loosen up with time and rougher conditions (terrain as much terrain as the child's weight or any other load). So please, don't take your Maxi-Cosi Gia or Joolz Aer on a dirt-road every week.
I was asked numerous times for an ultra-compact stroller that can handle an older, larger child (= with high weight capacity) and can even go through some terrain. This is false; physics doesn't work like this. And even if you find something you feel is approximately suitable, watch out and use it carefully enough not to end up with a rattling stroller after a few months in. Think about an ultra-compact as an occasional model filling out the need for something super simple for a vacation or a shopping trip, not more. If it will handle more, that's a bonus, but don't count on it. It is not meant to be used like that - it's primarily a travel solution.
Instead of the smallest size possible, though, I would strongly suggest looking at a suitable alternative. A mid-size, lightweight, quick-fold stroller with a forward-facing seat will be a relief from the large starter you don't want anymore. And it will fill out the needs of you as well as your child.