Very few things are more irritating to me than the cheap holiday lights.
Like on this string, some work, some don’t. Last year when I carefully put them away, all the strings worked, this year when I got them out, 3/4 of them didn’t work at all or 1/4 of the string worked or 1/2 the string worked. I have slowly been buying LED strings (none of those have stopped working yet). Although the LED light isn’t as cheery as the incandescent lights, at least they go on from year to year!