A common mistake homeowners make is thinking that if leaks are popping up often, the entire roof is bad and needs replacing. But repeated leaking can have more related with installation issues than the roof itself, and a proper repair will be a much more inexpensive choice.
When this happens, the first place to check is at penetration locations in the roof. Penetrations are places where holes are punched through the roof for things like pipe vents and chimneys. If leaks are showing up around penetrations, then you may have received a bad installation process. Depending on the number of penetrations, repairing the flashing will probably fix your issues more efficiently obviously much less expensive than completely replacing it.
If the leaks are penetrating seams in different roofing materials, then it could make more sense to replace rather than repair.