The Tenkara USA guy told me tenkara is even an oddball sport in Japan. However, it is fun some days - other days you get a good lesson in why reels were invented.
I've liked simple fixed line techniques for a long time. It is fun to simply strip down fishing to a stick, a line, and a hook/fly. Plus not having a reel or guides is great when it is below freezing.
Fish heads have refined simple pole fishing to suit local conditions all over the globe. I started by picking up crappie fishing down South. Yes it can be simple, but the pros get the wrinkles down and catch 10X what the average guy does. Met English match fishing guys in Illinios who did that well with river smallies. Those techniques use carefully shotted bobbers kind of like center pinning without the reel. Match rods cost big bucks, but the average guy version is the roach pole. But these handle carp and barbel which a re tough fish. Tenkara rods are very, very soft and are meant to toss unweighted soft hackles and you can't pick up a 6" trout out of the water. It is fly fishing sine you do throw the fly with the line. Crappie poles have a lot more beef - they are designed to pull slabs out of the weeds. BTW, crappie poles combined with English match fishing techniques are almost unfair in trout fishing and if you want to use indicators (bobbers) with nymphs and shot a crappie pole is a better option then tenkara IMHO - and it will only cost $10 to $20. There are fixed line pole setups for steelhead, carp, and saltwater where the fish are pretty hard fighting - but they are a far cry from tenkara even though they are a pole and a line.
I have used crappie poles alot and tenkara a little at the Pequest and have had no problems landing the trout there. I've talked to Pacific NW steelheaders who laughed when a Japanese guy can over with a simple rod for wild steelhead. But in the end he landed about 100% of his fish and the fly guys were about 50% so they had to eat a little crow. But once again, a tenkara rod is specialized to toss unweighted wet flies in small streams and the rods for big fish are a different thing altogether.