For typical beers, secondary isn't needed.
In truth, most homebrewers are referring to a 'bright tank' when they say secondary. The transfer to another vessel exposes the beer to oxygen and potentially unwanted organisms. At the homebrew level (volume, not quality), autolysis will not be an issue during the 2-4 weeks most homebrewers allow for fermentation and bulk conditioning. Even 2-4 months shouldn't be an issue. Large commercial fermenters create a ton of pressure on the spent yeast cake at the bottom. We don't have that.
True secondaries, as in secondary fermentation, are a different story. I'm about to do a brett'd stock ale. It'll get 4wks in the primary where the saccharomyces will do its job then drop to the bottom. At that point I'll transfer to a smaller vessel, all the way up to the neck, for the brettanomyces to slowly do their work over the next 8-10mo.