Minimalist golf can be fun, make a carry bag lighter and easier to get around the course with, and be and great "off season" means of learning to use various clubs as "multi-purpose tools". I carry the full 14 clubs allowed and even would carry more if the ROG permitted... even though I probably would not score any better. I own my own cart and ride at my 71 years of age. So, the added weight of a bag chuck full of clubs has no negative effect.
My cart partner, on the other hand, carries no more than 7 or 8 clubs... at the most. He usually bags Driver, 5-wood, 7-wood, 5, 7, 9, and putter. He has the entire set of irons from 3-SW. Yet, only bags the 5, 7, and 9. He struggles to break 90. Complains non-stop because he doesn't score better. And, during a round will be commenting "This club is going to go over the green, but the next one will leave me short....." I have suggested a number of times that he could cut a few strokes off his score if he would only put some additional "tools" in his bag of tricks. He is sold on his commitment to keep with the minimum number he feels he can get by with.
The point is, play what ever keeps the game fun for YOU! If you feel the minimalist bag provides all the help your game needs and still have fun playing this Game... go for it. OTOH, if you feel you score better having more choices... keep it that way.
My swing speed has diminished over the years and the gap between clubs has minimized. I would still prefer to use the same stroke on two different clubs for a shot to a pin than have to decide if I want to back of or go with full swing or punch or ...... Shoot! At this age, I have difficulty remembering what hole I'm on let along having to try to remember 6 different ways to uses one club!!! :>)