Maybe
Maybe if I make it to retirement age but that’s not gonna happen now. If I’m understanding correctly I shouldn’t need to carry so much spare parts and/or gear that I’d need a rack.
It is a sort of Catch-22 situation that the heavier you make you Jeep, the more likely it is to have mechanical failure, or get stuck. Modern jeeps are so complex that many failures are not fixable outside of a dealership (or similar). There is an argument for bringing spares for mechanical or electrical parts which are most likely to fail on the trail, and spare fluids. But there is only so much you can do, and Jeeps are not good at carrying a lot of weight or "stuff" in general.
If you are traveling with others, it may be that there is a skilled mechanic among them, but if there is not, then burdening the Jeep with many spare parts (many of which may be expensive or difficult to buy or replace under normal conditions) just in case they may fail does not make sense.
It is important to pack tow straps, jacks, battery jump pack, and whatever else is needed to get your Jeep to where a tow truck is willing to pick it up if possible. Normal towing like AAA is only willing to show up on normal roads, and off-road recovery can be very expensive.
Make sure that you have a means to call for help when there is no cell signal. Something like Garmin InReach is a good idea. If there is risk, then find someone else with a different vehicle to travel with you.
Backpackers are able to live for a week using what they are able to carry on their back. Dialing back on how you camp, and avoiding the modern overloaded "overland" approach, should allow a family of four to live out of a Jeep for st least as long as backpackers do. Use a ground tent, sleeping bags, camp stove, freeze-dried camp meals etc. Carry a lot of water, and in multiple containers. Water may be the most important thing that you carry.