@FancyNewt you are asking the wrong questions.
Will it improve my heart health? Will it reduce my risk of obesity related cancers? Will it improve my mobility? Will it increase my life span? These are the important questions to base your decision on starting any diet to "cure" your obesity whether it is pharmaceutically assisted or not.
Loss of muscle mass, sagging skin or any of the other side effects are, secondary, but still a worrying risk with any weight loss and can be helped at bit with exercise, strength training, nourishment, hydration etc. This is, partly along with the other unpleasant or serious side effects, why WLI are not the "easy" answer/decision.
Cosmetically a lot will depend on genetics, age, how long you have been overweight and by how much etc. Many of the Mounjaro/GLP facebook pages show before and after face pictures and some of the woman look fantastic and so much younger, others might now look their age rather than a more "youthful chunky" face looks, but they also imo look much healthier. If you had a choice between "looking" or "feeling" younger which do you choose?
Maintenance after weightloss using WLI or any diet is a concern I think we all have. We know if we return to our old habits and the weight will return. There is an option if we struggle to maintain after using WLI many pharmacies are offering the option of maintenance plans - taking lower doses or perhaps prescribing again for a month or two occasionally to get us back on track.
Good luck whatever you decide.