I could never understand the point of a gym. Just a pair of running shoes. Some dumbbells. I picked up slacklining and bosu ball training during the lockdown. Why does one need a "gym" ??
What's the point of restaurants when people have stoves and microwaves in their homes? It's a service, it provides convenience.
Sure, I could buy several hundred thousand dollars' worth of free weights, machines and kettle bells, and a treadmill, and install a big tv over it and get satellite cable, and somehow fit all of that and a sauna and a swimming pool into my tiny apartment, and have to worry about moving it all every time I move, and about maintenance and everything else, or I could just walk into any Gold's Gym on the planet and have nothing but the workout be my problem.
You don't need all that equipment to work the same muscle groups. Honestly, a $45 set of resistance bands is a great buy and these haven't experienced the same supply runs that heavy, more obvious equipment has experienced.
Resistance bands are not even close to real weights. The feel is completely different and the resistance scales in a way that is counter productive for a lot of exercises. You don't have a constant measure of strength and progressive overload is impossible. Resistance bands are already as a supplement to free weight training but you can't get the same experience.
A circuit workout maximizes efficiency. Machines isolate muscle groups. Similar results can be achieved with free weights, but that requires paying attention to form, which is difficult at exertion limits. It is difficult to break form on a machine. Hence, machines can enable you to overtrain but they are also excellent at preventing injuries.
If you regularly lift truly heavy weight, you need a squat rack and a rubber floor capable of sustaining equipment drops.
Going from a dedicated machine to another dedicated machine is faster than reconfiguring a universal machine like a Bowflex. Pace matters in a workout. Rests are regulated.
I own variable weight equipment. Someone sold me a set of Turbobells, which scale from 5 to 60 pounds per hand. It is a great system similar to Bowflex Selectech. My workouts require using 3 progressively heavier weights. It is a common body building technique.
So, for my arms I need 10, 12.5, and 15 pounds. Some exercises are 15, 17.5, and 20 pounds. My legs are stronger, so I use 35, 40, and 45 pounds. If I didn't have an adjustable set, this would be a lot of free weights and good luck finding fractional sizes in a store.
Gyms usually have good air flow, at least at the gyms where I am a member. Many have amenities like swimming pool, whirlpool, massage chairs and so on.
Dropping weights at a gym is annoyance. Doing so in an apartment above neighbors is evictable.
People whose goal is to lose weight do not need a gym.
Completing my workout with a set of dedicated weights at 2am when I have the gym to myself is at least 20 minutes faster than with my adjustable weights. So, using a gym also saves time.
Costs to replicate a gym:
1. 8x4 1" gym mat - about $150, weighs over 100lb - just looked into this last week. 6x3' horse stall mats are decent also.
2. Free weights - a few hundred all-in
3. 8' Mirror - not cheap and yes they are necessary
4. Adjustable bench - over $100
5. Gym-like variable height adjustable treadmills are not cheap
All of this takes space to store. If you do not have excess space, that adds to setup and teardown time.
Sure, I could buy several hundred thousand dollars' worth of free weights, machines and kettle bells, and a treadmill, and install a big tv over it and get satellite cable, and somehow fit all of that and a sauna and a swimming pool into my tiny apartment, and have to worry about moving it all every time I move, and about maintenance and everything else, or I could just walk into any Gold's Gym on the planet and have nothing but the workout be my problem.