It depends on quality of the stuff.
My findings are that the big companies do not produce really high quality clothes anymore.
My US made Ralph Lauren Bayport cotton jacket is over 20 years with me. A Diesel jeans jacket nearly 30 years.
A Levis 501 nearly 20 years.
A Hilfiger jeans has fallen apart within 3 years. Their shirts last much, much longer.
Yes, unfortunately I think you're right about quality going down at big companies. In particular, I think Boss stuff is very hit or miss. I have a pair of leather gloves that are about 15 years old and they remain fantastic but a more recent purchase of a pair of knit gloves was very disappointing. Boss socks are typically fantastic too, and I have many pairs that are probably at least 10 years old and still worn regularly. Also a big fan of Boss neckties. But with one notable exception, I've been disappointed how well Boss chinos and jeans hold up.
I've been disappointed with Levi's and Dockers the last several years too. My Levi's of choice are 505s, but they are so variable when it comes to fit I find that they really need to be tried on before buying. Still love my Docker's K-1s, but those must be getting close to 15 years old at this point. Uniqlo is usually excellent quality for the price, but I recently had a very nice looking pair of chinos that were developing holes by the back pockets after less than 10 wearings.
Lacoste quality is generally quite good in my opinion, and if you're able to score something you like on clearance the brand can provide excellent value. I have several polos that are more than 10 years old and only one is past the point of looking presentable. Lacoste's chinos are excellent, and they are probably the best pants I've found.