That said, you only need a rack, a bar, a bench, and some plates to get the best possible workout with weights. Doing squats, deadlifts, bench press, rows, and olympic lifts is all it takes to become extremely strong and hardened against injuries. Machines are totally unnecessary.
And I'm not even so sure about fighters. Which fighters do you have in mind that explicitly don't do weight training?
The fighters at my gym.
I guess I can't say for certain what the pros do or do not, but I assume some of the competition amateurs I see are doing the best they can. And they look like it. And I know that guys like Conor McGregor have made statements about doing purely "functional exercise". I'm sure some pro fighters weight-train, because it has obvious benefits. It's also hard to sustain muscle in a cardio-focussed sport.
I'm definitely a weight-training advocate, as well. I'm a believer that in order to "get stronger" you have lift heavier and heavier things. That's only really feasible at the gym. I try to get there a couple times a week.
On the other hand, so many people who are starting out try to get some heavy duty "system" in place before they feel they can begin. I see these people at the gym; there for 2 hours, putting everything in their phone, not even working up a sweat. It's not that complicated; just do work.
Machines are actually worse than free weights; you don't get a full body workout, especially all those stabilizer muscles that help prevent injury.
> hardened against injuries.
I can second this; while I've not become extremely strong, I credit strength training for my lack of broken bones after taking a 600ft tumble down a hard pack snow slope. Strength training in recovery also helped me heal faster.
Yes and no. Free weights are the better of the two choices, but machines are head and shoulders better than free weights for solo trainer safety, which is a problem for us guys and gals trying to "fit it in" to our schedules, as well as beginners.
So, I don't discourage people from machines simply because they aren't optimal. They have their place. I generally use the rack to bench. I love the AirDyne and Concept 2, if those count!
Any exercise is better than no exercise. And yeah, things like bench press you should ideally have a spotter for. Myself, I stick to the five lifts from Rippetoe's "Starting Strength" (a recommendation I got from HN of all places!), so squats I use a power rack with pins, and overhead press, deadlift and power clean need no spotters. Bench you can do without a spotter if you leave the collars off (just dump the plates on one side, then the other), but most gyms frown on that.
Who said anything about building serious mass? There are many, say, professional fighters who do very little weight training and they look exceptional (literally).
You want to get in shape, you don't need a gym. Do hard work for 30 minutes a day. Work that makes you sweaty and tired. Run, sprint, pushups, burpees, anything. You will get in shape. If you don't believe it, try it for a couple months.