I dont watch much podcasts but the SM7 has been around a long time, maybe we just notice mics more? but YES SM7b and Re20 seem to be the most common. SM7b is a battle tank tough part, its luckily fairly cheap and like the SM57 , 58 is amazing. The RE20 is often chrome or gold plated when I see it on Sports casts these days , but its got its market share.
I think theres the "big boy pants" too with the SM7 that is a sales point, versus having a SM58 on the stand in fornt of a desk speaker.
A SM58 would work pretty well and sound nearly identical for $99. But would it look "pro"?
Nuemann makes the type mic but I guess it didnt take off or replace anyone....they hold the LDC top position with everyone and their brother trying to make a clone of it in some way it seems. Its funny how some lock in their "spot" in the mic world but cant do much else when they try to expand.
MXL has the $69-$99 one that really didnt sound that bad to me if you had the gain and never moved, it was actually quieter and had some nice sparkle in the highs.....but its always to be compared to the SM7b and RE20. (which MXL had in mind I think in the design)
Ive probably had the SM7b 4 or 5 times...sell it buy it sell it trade it buy it....I think my first was $225, new was around $275..$300...used could get to $175 because I suspect some people would plug the SM7b in ....a say YUUUKKK!??? WTF????? and dump it. lol