Possibly more useful for debug & repair than design - if all you care about is the temp of a single point then yes an IR thermometer is adequate.
A TIC is Extremely good at finding shorts on a PCB - throw some current into it and the path of the short just lights up.
Similarly if excess current is being drawn by a component, you can see it instantly.
Other applications would include measuring the effectivness of heatsinking as you can see the thermal gradients.
Can also be useful for monitoring temp while doing hot-air rework.
It's also just a fun toy to have