TLRs are very good, but you will find that SLRs are better. Take a look at Hasselblads which has interchangeable lenses and changeable film backs which most TLRs do not have.
Oh, sure! MF SLRs (Hasselblad) = fiddly bits, high costs to purchase same, clunky shutter/blind system. Endless repairs. Here in Australia, 'blad servicing is calculated in A$200 increments, one little thing, $200, another little thing, $200 more, and so on. Endless money down the drain. So you end up buying secondhand, often as not a pro camera almost on its last legs, eighty to ninety per cent dead. You'll get to know your camera service center well. An ideal kit for boys who like to play with toys.
I was into Hasselblads for about ten years and eventually sold out. Bought three before I finally lucked into a 500CM owned by an amateur and carefully used. Made some money on the camera when I sold it, but took losses on the accessories. End result, I was down about $2,000 overall.
MF TLRs. (Rolleiflex, Rolleicord) = simple cameras, reasonable costs to purchase same unless you want the legendary 2.8 models with two thirds of a stop more and higher prices, not for me! Accessories available at good prices. Easy loading, no fiddly backs to attach. So no changeable backs,so what? My Rolleiflex T and Rolleicord Vb have 16 exposure insert kits and I also have a circa 1950 35mm back which fits on any Rollei. So no intechangeable lenses, have you priced a good 50mm or 40mm Zeiss for a Hasselblad? Even a secondhand 50 in good condition is worth more than any two of my Rolleis. Resale value for TLRs stays reasonable, but beyond saying this,I wouldn't know or care, as I've never sold any of my user Rolleis. I used them regularly and they just keep on going, even the 1962 3.5 E2 I bought 51 years ago.
This isn't meant to disparage what Sirius Glass wrote, his viewpoint is only one of many, mine differs. I've owned Rolleis since 1966, put them aside for a decade when I got into Hasselblads, now using them again.They are a joy to work with and always produce the goods.
In the end, it's all horses for courses, and some common sense.