Mounting to the stud is not what you want to do. What you want to do is straddle studs with 3/4" ply for blocking, which is what you mount to.
If the builder had the wherewithal to provide blocking, which I’ll agree is mandatory for anything bigger than 55" (and a 2x8 or 2x10 spanned between the stud bays is a bit better, it provides more meat for the lags to sink into and most jobsites will have some in a scrap pile). But for 55" and smaller, 5/16" x 2" lags into the 2x4 studs is plenty sufficient. Ply works if you want to use toggle bolts, but you have to notch it into the stud for the drywall to sit flat.
It definitely happens, though rarely for a living room or family room. Usually smaller ones are in kitchens, bathrooms, garages, kids rooms, offices, etc.
If the builder had the wherewithal to provide blocking, which I’ll agree is mandatory for anything bigger than 55" (and a 2x8 or 2x10 spanned between the stud bays is a bit better, it provides more meat for the lags to sink into and most jobsites will have some in a scrap pile). But for 55" and smaller, 5/16" x 2" lags into the 2x4 studs is plenty sufficient. Ply works if you want to use toggle bolts, but you have to notch it into the stud for the drywall to sit flat.
Yeah but… Who is wall mounting smaller than a 55" these days?
It definitely happens, though rarely for a living room or family room. Usually smaller ones are in kitchens, bathrooms, garages, kids rooms, offices, etc.