Most steel alloys used for bicycle frame tubes these days lend themselves to both brazing and welding; the amount of heat involved is virtually a non issue.

Virtually any tubeset can be TIG welded or fillet brazed together, but for lugs the outside diameters are constrained somewhat.

All joining methods are viable and none offers any significant advantage from a durability standpoint (assuming the person joining the tubes knows what they are doing).

In my opinion, TIG makes sense for race bikes since lightweight, large diameter tubes can be used. Fillet brazed can be used on this type of frame as well but it requires more skill on behalf of the builder and is more expensive and time consuming to execute.

Lugged frames are aesthetically pleasing to many riders and since these frames use small(er) tube sizes, they tend to have nicer ride qualities than race frames using super OS tube diameters.

In the end the choice of which joining method should be a secondary decision, not a primary one, depending on what you want from the frame. And don’t forget the builders typically have their specialty so it’s best to not stray too far from what they know best.