When I got my IR ticket some years ago, an American friend congratulated me on becoming a REAL pilot.
"Of course", he said, "now that you're a REAL pilot, you can get into REAL trouble, REAL fast!"
With a properly equipped aircraft, the IR is a valuable addition to the skills required to keep in the air. It is not, however, the panacea it is often thought to be as a solution to all kinds of weather difficulties and is, as noted already, a perishable skill that needs to be kept sharp.
Without it, however, there is absolutely no point considering anything other than VMC and adhering to sound decision-making.
Not to be holier-than-thou, of course, I can remember some of my earlier days when that advice wasn't listened to either. There but for the grace of God.........
Better to be on the ground wishing you were flying than to be flying and wishing you were on the ground.