That's the worst assumption you've made all day, lets see now:
https://www.youtube.com/watch?v=q5TD...dyZmnXC-pUrwxw - Titan HM tanked by a WHM in 2.0.
https://www.youtube.com/watch?v=tLF6...dyZmnXC-pUrwxw - Titan EX solo healed fairly early in 2.1.
I also did weekly sales of SCOB (Effectively undersized before that officially became a thing since the buyer would die in a corner somewhere), solo healed a couple of Gordias turns during progression because my co healer couldn't make it. The reason I don't typically make a song and dance about this, is because I've always paired up with big DPS co healers to feed my healing addiction. I'm not far off solo healing every single weekly lockout thank you very much (and thus why my logs HPS rankings are consistently so high). If we want to go really far back, I had solo scalps going back as far as EQ including the likes of one of PoFear Golems (the one that doesn't DT) and Phara'Dar again, whilst they were still considered valid content aka before Planes of Power.
TLDR, I suspect I solo heal a lot more than you do son ;)