Katy runs on I-10. The commute into the Energy Corridor and downtown means real highway miles every day, and highway miles are where paint takes the most abuse: brake dust, metal particles thrown off construction, and bug strike at speed. Iron fallout from that traffic embeds into the clear coat and is not something a normal wash removes.
The master-planned neighborhoods out here, Cinco Ranch and the developments around it, are the easiest kind of job for a mobile detailer. Wide driveways, room to work, and enough space to do the car properly without blocking anyone in.
Being inland does not keep salt off the paint. Gulf air carries far enough west that cars in Katy still pick it up, and combined with the humidity it is why protection lasts less time here than the label on the bottle suggests.
There is almost always roadwork somewhere on this side. The I-10 and Grand Parkway corridors have been under continuous widening and resurfacing for years, and construction zones throw grit, tar and overspray onto everything driving past them. Tar spotting along the lower doors and behind the wheels is the giveaway, and it is a solvent job rather than a wash.
Contamination that has bonded into the clear coat needs decontamination rather than another wash. Paint correction removes it, and a ceramic coating is what stops it bonding again.