Some of my favorite beers are very simple recipes with technique that make up for it.
+1 to this. I know a lot of brewers have a "kitchen sink" approach to grainbills and hopping schedules, which to me glosses over the most important component of the brewing process--the PROCESS. There's so much you can do just by changing your brewing technique--temps, rests, ferment schedule, etc. that will make your beers truly yours.
One thing I like to do is to periodically (like every three months or so) brew through my three "stock" beers--an ESB, a stout and a brown ale. I've made these beers probably 25x a piece over the last several years, but each time I try something a little different--instead of a single-rest mash, I try a multi-stage mash, or instead of a 60 minute hop addition, I try a FWH addition. I add a lb. of biscuit, or victory, or whatever other type of malt seems interesting, just to see how it changes my result. I know pretty well what my base beer will taste like for these three, so if, for example, I increase my mash rest to 156F from 153F, I can figure out how that changes the result.
These three are my basic test beers because they're the ones I like the most, English ales that are in my favorite styles. Other folks undoubtedly do the same with American-style IPAs, or dunkels, or whatever. No matter the beer style you can create huge variations by making changes to your process.
Maybe pick a single beer style and try to make as many different versions of it as you can (high gravity/low gravity, high IBU/low IBU, malt forward/hop forward, American yeast/English yeast/continental yeast, single rest/multistage infusion rest/decoction, etc). You could make small batches (like 1 gal) of each so you don't end up with 40 gal of one style of beer. I would guess you'll be surprised at how much variety you have available once you think about how you can change your process, how many different beers you can make that are all within one category.