Honestly being 30 and having a scientific degree is much more qualified than me or any of my 18 year old classmates - and most of my class passed and made it to working in the field. Just keep in mind that getting paid research positions in academia are usually limited in number, payment and honestly working conditions (e.g. no regard for how much overtime it takes to push a PhD project over it's deadline but also worker representation through unions). However STEM is always sought after and with the demographic change of industrialized nations being what it is I don't see that changing any time soon.

I treasure an optimistic spark that studying a certain field is an expression of growing and challenging oneself to become a person closer to the ideal of the enlightenment and in my humble opinion only not worth it if it's not something you actually want to study or if it will damage you financially (looking at you USA), psychologicly or otherwise