You can be out of the gym in 30 minutes or less. It's 3 exercises 3 times per week. 15 sets total per gym session (not counting warm-up sets).
The whole point is to start with a very low weight (empty bar) and work your way up by adding 2.5lbs to each side every time you go back in. It's the fastest linear progression workout for beginners.
From my experience, Strong Lifts 5x5 is the recommended beginner's workout. You need a solid base to start off with. and 5x5 gets you there the quickest, because you are doing compound lifts. Biggest gym noob mistake is to go in there and start doing isolation exercises, when you are already lacking a base. That causes muscle imbalances which can then result in tendon and joint issues.
Edit: Just wanted to add that the 5x5 can transition into 3x5 and then 1x5 as you move up in weight and plateau. This can keep you going until you squat 400-500 pounds and deadlift 500-600.
I think 30 minutes in the gym is disingenuous. Within weeks that quickly balloons to about 1.5 hours as soon as the weights get remotely challenging.
Very very very few people can continue even a 1x5 linear progression to a 400# squat or 500# deadlift.
But I'd like to understand better your concern about volume. If I face this deficiency, what will it feel like? How should I get around it?