I’ve seen quite a few people carrying staplers and removers as well as utensils to perform minor surgeries or perhaps bullet removal.
You need to get a lot of knowledge to really know what you need. For instance, bullet removal is not a thing you need to worry about. I've had one in my for almost 20 years now. The doctor told me the only time you remove bullets is if you're in a western movie.
Nor are you likely to survive a gunshot wound without advanced medical knowledge, anti-biotics etc anyway.
The best place to start if your just a normal person with no medical training is with the equipment you already actually know how to use. Bandaids, over the counter pain killers, anti-biotics creams, Anti-fungals (this can be a big one) etc.
Go to your local Target and get a bunch of their generic over the counter treatments for the things you've actually used in your life. The same stuff you probably already have...but as a prepper you get much more of it, and package it for easy access rather than having a tube of this, and a bottle of that scattered around your house.
Note, this is going to be quality of life stuff, not anything that is life saving in itself but that is still an important thing to manage. Chaffing or athelets foot can disable you. Sunburn can disable you. An ingrown toenail can disable you.
Surgical gear, serious bleeding control or airway management etc is next to useless without the training for it. Once you get that training you will know what you need for yourself...and probably realize that without a hospital to go to its still mostly useless. Even advanced first aid doesn't 'fix' anything, it just stabilizes it until hospital can provide treatment.
Most pre-built kits are pretty useless to someone who actually knows what they are doing....which is part of the problem with pre-built kits. People with the training don't buy them...so they are mostly marketed to people who don't know what they are doing, and therefor don't need to have the right stuff because those customers don't know any better...and those customers never find out because 99.9% of them never actually need to use any of the stuff they just bought, compared to an EMT's truama bag that he or she builds and adapts from the experiences of treating actual trauma.
Here are some tips though.
Less kinds of stuff, more of what you do have. Instead of one of 40 different things in the bag, have 10 copies of four things.
For instance. I have NEVER used anything but a large and medium oral airway. Having the full size set is a waste of space. I have never used a stethoscope in the field on a trauma. Never used those little pen lights. Never used a CPR pocket mask. But 4x4s? You can use dozens of those on a single call. 'Kling' wrap and tape? Multiple rolls, on one patient. Kling is like duct tape for EMTs, we put that stuff on everything. Rubberized 'vet tape' is one of the best things ever as well. My EMT coat has a roll in every pocket.
If you really want medical training look into an EMT class. These usually cost between $1-5k and take about three months to complete. Ideally you would also sign up for some shifts with your local ambulance service. As they will tell you the class and license is just the start of learning, just enough knowledge to get your foot in the door, you only really get good at using it from experience.