Each of the top 4 seeds gets their own quarter, with all things going to seeding would put 1-4 and 2-3 as the semifinals which all makes sense. But the Slams seed down to the third round (32), but don’t maintain this pattern, at least not completely. For example, in the US Open Men’s Singles this year, the first couple seed matchups in the third round are 1-26 (not 1-32), 16-24 (not 16-17), and 12-19 (not 9-24). They still maintain each seed having their own slice below the third round, just curious as to why they randomly distribute 5 through 32 through these slices of the draw.
It’s not fully random after seeds 1-4. I believe 5-8 occupy the same 4 spots in the draw, but they are random drawn across those spots. Then 9-16 is another random draw across 8 spots and so on. The randomness prevents players from seeing the same matchups all the time if their rankings were to stay the same. It also prevents match fixing to avoid or set a particular matchup. Say #30 matched up poorly against #3, so they deliberately lost a prior match to drop to 31 and get a different matchup. It would be bad for the sport if that was allowed to happen.