Some really excellent advice in the threads above, absorb all the info. No rush, unless you're older than 40. Aviation degree is basically useless to be brutally blunt. Many get an aviation degree as a 'back up plan, or fallback' but if the pilot market is in turmoil, then bet your bottom dollar that every single affiliated aviation job is also in turmoil! A pilot or aviation degree soon becomes useless if every part of the industry is suffering. Genuinely more sensible becoming a sparky! Also, if getting a degree adds more money to the final bill, then it's just more debt to pay at the end of the day.
ATPL ground school is comparable to a 4 year uni degree getting crammed into 8 months or less. You don't *need* to be academically smart to get through ground school. Sure, it'll help! But as you've mentioned, it's the volume of info thats difficult, not necessarily the content (especially as you're actually interested in learning the subject, as apposed to being forced to learn pythagorus in school!).
I have no stats, but 85% plus in EVERY subject could actually be a tough ask. Probably many do get that these days with the help of the various ATPL question banks which assist candidates along the way.
Last note from me as an ex base capt involved in recruiting, sometimes the grades and where you train are the least interesting part of a candidate. We wanted to know if a pilot could put up with sitting beside someone in a tube for hours on end and have a good day out. Could've paid the most money in the UK for a licence and went to the apparent best school but if you have no personality and are socially awkward then that will be of concern.