Friction shifting removes barriers to feeling a higher level of precision in shifting gears, if you have any interest in that.
I have a custom 650B I built with an indexed 9-speed drivetrain. I have been riding in that mode since new, and it still functions very well. It is mindless and works with a snap-click, which goes along with the definite click, click, click of the Silver rear cassette hub's ratchet.
My orangesicle Rambouillet and its mosaic drivetrain has Suntour Accushift bar end shifters directing a Mavic 841/5 RD on a Shimano 8-speed XT freehub with a 13-30 cassette and Mavic 860 FD between 46/34 rings on the TA Zephyr cranks.
The concoction of that drivetrain is an environment where friction permits me to appreciate the value of these many iconic parts' operation. Under way, I hit shifts with quiet accuracy by feel and lever position. Between the very quiet shifts and the free hub's very muffled ratcheting, it is a bike that highlights any extraneous sounds and makes me aware of how audible any proximate modern bikes' drivetrains are as they operate.
Andy Cheatham
Pittsbugh