In my experience, you need a range of ways to cut mortices and tenons, if your principal tool is the router.
I have a router morticing jig that slips over the jaws of my vice. It has a registration stop that can be fixed in a number of different positions, and travel stops to limit the length of the mortice. The jaws are faced with formica so I can mark on them with a pencil for pieces too long to register against the stop. It does not rely on having a base for the router, so there is no loss of cutting depth. It is superb, and I'll often reach for it in preference to my "proper" mortiser.
But if I need to rout a mortice across the grain, I need a different setup. So I have a guided which can be clamped across my board, again with travel stops. I don't think there is any one machine that does everything. But the point is that solutions like these are easy to make and perform very well indeed, without having to spend a lot of money.
As far as the matching tenon goes, I don't use the router now, becasue I have the Ultimate Tenon Jig, but when the router was my main power tool I had one jig that worked well on the router table, suitable for smallish workpieces, another which cut vertically (like the Leigh) which was great for angled tenons (but limited by how high off the floor I could work) and yet another for routing big tenons on long lengths like bed rails.
Horses for courses. The may not be as fast as a tenoner, but for us hobbyists, speed is rarely an important concern, is it? We are more interested in enjoying the process and not having to spend very much!
S