I can't disagree, however as I stated I "could" build anything I have done using hand tools only. However my purchase of my tools and equipment allows me to do the same things faster and with much less effort and in my case more accurately. It is a pleasure to rip a board on my Unisaw or planer and measure it to find it is within a few thousands of an inch of my target value.
I practiced making dovetails with my Lee Neilsen saw. I can do it but it is so much faster and more consistent with my Leigh Jig. The amount of work my son and I do certainly don't justify purchase of these tools, but it is a joy to me when using them.
Luckily my son is quite interested in woodworking so the investment in my shop and tools will somewhat be justified over my and his life.