A full-time gig driver logging 30,000-40,000 miles a year drives roughly three times a typical commuter's 10,000-13,000 miles, so every mileage-based interval arrives about three times as often on the calendar even though the interval itself has not changed. At 35,000 miles a year, the severe-service oil interval of 3,750-5,000 miles comes around every 5.6-7.4 weeks, not every few months. The same shrinking hits other services: tire rotation every 7-11 weeks, front brake pads every 5-8.5 months (versus 15,000-25,000 miles under stop-and-go duty), tires (tread life) every 14-17 months instead of several years, and transmission fluid every 10-20 months on a 30,000-60,000 mile severe schedule.
Rideshare and delivery driving meets manufacturer severe-service criteria almost exactly: extensive idling or stop-and-go traffic, frequent short trips under 10 miles, and extended time carrying passengers or cargo - use the severe-service numbers in the owner's manual, or the shorter end of any interval range if only one schedule is listed. A skipped $80 oil change does not save money, it trades a scheduled cost for an unscheduled one on the vehicle the income depends on. Vehicle expenses including maintenance can be part of what is deductible under the actual-expense method rather than the standard mileage rate (the two generally cannot be mixed for the same vehicle in a year) - this is not tax advice, and dated, itemized records are worth keeping either way.