There are so many ways/methods to get the carpet clean. There isn't one best method for every company. There are enough bad TM cleaners out there that you could keep busy with customers that have never been happy with "steam" cleaning. Use padding/encapping as your main method and you could build a profitable business without the need for a TM. There are quite a few franchises out there now which are doing it.
I use a TM and set up my pump out on every big job. Around here, every house has a clean out opening in the front yard for they pipes. You remove a plastic cap and put the pump out hose in - adds at most 5 minutes to a job.