The old style friction shifters should also be much easier to maintain and repair. Modern indexed shifters are more likely to have issues where due to cable and housing stretch the indexing gets unaligned and you have to adjust it periodically. This might not be an issue any more with electronic shifting components. On the other hand, those are expensive and require battery power, so you need to remember to recharge. Fiction shifters also allow you to trim by feel and sound to always get the perfect chain position. The pathlesspedaled youtube channel has many videos on the advantages of friction shifters for causal riders and touring cyclists.

Electronic shifters don't have any issue with cable stretch and typically don't need any adjustment once they're setup on a bike. Also, electronic shifters automatically adjust the trim on the front derailleur so that the chain line is optimal.

After >16000km mileage, my Shimano Saint shifter gave up on me 50km into a 200km audax. It is easier to shift gears with an indexed shifter. However, audax riding requires higher reliability. My 35-349 wheels (I'm riding a Brompton clone) makes it hard for me to install modern electronic shifting, except maybe Ltwoo's AE.

I've since switched to a Microshift 12S mountain bike friction shifter. Quite happy so far. It has click mode and pure friction. With my Shimano Saint derailleur (10s), due to the clutch, it took me some getting used to due to the hand strength needed. A spare friction shifter is also lighter to carry. An unintentional plus point is the ability to move to an 11s (jockey wheels on the Saint derailleurs seems to be able to work with 11s chain) the next time my cassette and chain needs replacing. 11s will give me less dead zone in between each shift.

Vis-a-vis an index shifter, I like it that I now have a way (apart from cadence, gradient and speed data from my bike comp) to know approximately which gear I'm at by just feeling the lever position. With the time I've had with this setup, I'm almost always able to shift whatever gear by muscle memory.

In reality, for my city's (Saigon) traffic, I find myself shifting gears more and hence my hands does get a bit sore. The bumps and uneven drain holes can also cause the friction shifter to shift unintentionally. I could tighten it but it'd at the expense of my hand comfort.

However, in an ultra distance ride (>=200km), there's less gear shifts and hence less of an issue. I'm also able to use both hands to take turns shifting gears which is more important on a super long ride.

However, there are situations where you would want numbered gears. My road bike has Di2 electronic shifters and I set it to synchro shifting mode. This means that it'll do a double shift - front chainring and rear cassette - when shifting down a gear at the selected cross-over point (can be changed according to preferences and gear setups). This means that I like to know when I'm in the lowest gear before a double-shift as I'd rather not be out of the saddle and putting down power during that shift. What I do is I use an MT800 gear display which shows the Di2 charge level and current gear (it also provides bluetooth connectivity).

Incidentally, I'm surprised that you like unindexed shifters - they're a lot more clumsy than correctly adjusted indexed shifters.