the first one is a switch mode regulator, the second is a LDO linear regulator.
A simple power supply design is to use a LDO as it needs the minimum of support passives, but has limitations in how much power it can burn up to regulate your voltage - so doesn’t handle large drops from VIN down to the output voltage.
If you’re doing a switch mode power supply (SMPS) then you need more to surround the supply - usually as a minimum you’ll need an inductor as that’s what is doing the up/down conversion.
So, by looking at your DP design. The 5V uses a switched regulator, the 3v3 doesn’t. After reading about it I would assume this design is because the 5V accepts a much higher input voltage; thus a linear one would generate a lot of heat. The 3v3 is feed of the 5v; since there is such a small difference in voltage not a lot of heat is generated…?