Tito vs Roy represented a huge problem that has happened to many of the great fighters of this era. Tito at this point is just a blown up Welterweight. He had a huge power advantage at his best weights of 147 and 154. Roy was simply just too big for Trinidad and really Trinidad does not have the power to hurt Roy. Similarly Bernard Hopkins was also too big for Tito. This seems to be a trend of many of the great fighters of this era. They go up too high and get beaten because they don't have the power to hurt the other fighter any more. Sugar Shane Mosley was the truth when he first started. 32-0 and a total beast at his natural weight. Forrest may have been a stylistic problem, but Mosley had no business fighting Winky Wright. Similarly Oscar De La Hoya had no business fighting Bernard Hopkins. Hopkins could have been fighting at 168 or 175 for a while now. If Trinidad, mosley, and De La Hoya had just stayed at their natural weights they could have retired with amazing records.
Most of those guys couldn't make the weight any longer. Trinidad was having problems making 147 for awhile when he finally moved up in 2000. He had gone to 154 back in 1997 to fight Troy Waters in an eliminator (hoping to face Terry Norris), but went back down to 147 for the big paydays (De La Hoya) which he finally got in 1999. De La Hoya was very big in the lower weight classes (140 and below). It's hard to picture someone with his height and frame staying at those weights for that much longer. Mosley left 135 to chase the big money fight with Oscar @ 147, and went to 154 to again chase the big money fight with Oscar, but I don't see him staying that much longer at 135 based on his size as well. It's not a modern era trend, it's nothing new for fighters to move up in weight because they have trouble making the weight or there's big money in other weight classes.