Use a larger hose for bulky debris and a smaller hose when reach, flexibility or tool connection matters more. The important part is matching the vacuum, accessory and job.
A 2-1/2-inch hose is good at swallowing bigger debris
The RIDGID WD1450 uses 2-1/2-inch accessories. RIDGID specifically notes that the large hose size helps resist clogging.
Smaller hoses can be easier to handle
A narrower hose can be more convenient for car interiors, sanders and other hand tools. The tradeoff is that it is easier to clog with large chips and it creates more restriction.
Tool dust collection is a separate question
If you are connecting a sander, miter saw or router, the best hose is often the one that connects securely to the tool and gives the tool enough airflow without dragging a giant hose around.
Measure the connection, not just the hose body
Wet/dry vac accessory sizes are often described by nominal hose diameter, but locking collars, cuffs and proprietary fittings still vary. Check the model and accessory system before assuming any 2-1/2-inch hose snaps onto any 2-1/2-inch vac.
Choose by debris size first
Bulky wood chips, leaves and construction debris favor a larger hose because there is more room for material to pass without bridging. Fine dust from a hand sander may be easier to manage with a smaller, lighter hose.
Choose by mobility second
A big stiff hose can make a small hand tool miserable to use. If dust collection is the goal, a short flexible adapter hose can let the large shop vac stay on the floor while the tool remains easy to move.
Watch the total adapter chain
Every reducer, swivel and quick-connect adds another joint that can leak or clog. Use enough adapters to make the system fit, but do not build a plumbing sculpture if one correct cuff would do the job.