The FIRE mentality is just wagecuck to aspiring retiree.
If you cut down on your 4 or 5 biggest expenses, you can basically guarantee that level of living standard forever, provided that you take what's left over and invest it. If you save 3/4 of your income, you can get it done in 4 years. 1/2 of your income, 12 years. 12 years is far more doable for most.
It provides you a way out of the wagecuck life, but for most people it is not a pleasant way to live. No one wants to have a room mate when they are old, no one wants to get around town on foot or by bus when they are old. Also women tend to by nature be consumers, so the biggest windmill you have to tilt at involves getting your woman on board with this. Sometimes that is impossible.
No, not everyone can pull it off. It generally helps if you make 60k a year or more in an area without a very high cost of living and you don't have kids, which hilariously is a bigger problem because it ensures that that kind of thinking eventually dies out.
The biggest expenses generally being something like
Medical - get insured and dont get sick lol
Health - should be a byproduct of lifestyle, do some strength training, some cardio, "eat healthy", get enough sleep, don't be too fat, don't gain too much weight in general etc. This ties in to medical, ie don't get sick.
Food - generally lighter on the meat because that's expensive, stick to big staples like beans, oatmeal, rice, lentils, etc. I make a lot from scratch, but I'd rather eat nothing but ground beef and homemade bread than seriously sit down and eat a pound of lentils over rice. To me, it was disgusting.
Transportation - basically travel using bikes or the city bus. Every mile you drive with a car costs approximately 65 cents per mile, all costs considered. This adds up. A good compromise is an electric bike, or even an electric car (provided you live in an area that isn't hostile to those lithium batteries and the cost of electricity isn't astronomical).
Housing - do the math on whether or not renting or owning is a better deal, and get a room mate (more is better).
Entertainment - stick to free hobbies, cheap hobbies, or hobbies that make you money. A library card is your friend. Avoid subscription anything, it is better to buy equipment and lift with that than it is to get a gym membership with this line of thinking.
Children - don't have them, or just have one. The FIRE mentality is diseased in this respect because it tends to use environmentalism to justify not having kids, because muh carbon footprint.
It would be silly to not incorporate some of these aspects into how you live your life.
However, my wagecuck compromise here is to do 50 bucks a week into a brokerage account that buys nothing but index funds. After 30 years you will have upwards of half a million dollars. This does not include other things that you should be doing like 401k through your job, health savings account, etc. Obviously, earlier is better. If you can get your kids started mowing lawns and doing this at the age of 15, by the time they are 55 they will have 1.2 million.
Between government programs, retirement accounts, and the 50 bucks a week retirement plan, you should be comfortable.