No, you are not the only one. I invite you to read the following links:
I've read up a bit on it and it seems that the reason for the new installer is that the old installer was unmaintainable and a bit too sparsely documented to be of any further use. Also changes to the installer would involve an immense amount of work
Yes, the new installer is a bit flakey, not even half as good as the old installer, it has some bugs and it is a bit of a highly complex bloated sluggish pig (it seems to be a snap) but we'll have to do with it because it is, AFAIK, relatively fast and easy to build to the needed specifications and changes to it seem much less timeconsuming than with the old one.
The drawback of this complexity makes it very picky on which systems it wants to run, on top of the fact that the installer forces GPT on any disk (which results in several legacy systems not able to install anymore because not every BIOS followed the standard 100%) and that it eats a lot of RAM and CPU.
Since the installer is so new, I have high hopes that the 24.04.1 pointrelease will have most of the installerbugs ironed out.
Until that time you might want to install an older version and do a "do-release-upgrade" from there.