I’ve been using Voice Dream Reader on my iPhone for this sort of thing. I’ve only started using it recently so can’t give an in depth review but it works very well and the voices are pretty good quality.

for iOS (and I believe it is also available on android, but I am not sure), VoiceDream reader has been the best one I have used.

I dn't know how to get PDFs reading like ebooks as PDFs are quite a mixed bag. You can try and read them using the MS Edge browser which I quite like for PDF viewing.

If you're on Android, try TTS readers like Voice aloud reader
If on windows PC, try Microsoft ReadAloud

you can send pdf to Kindle's personal document service.
You can convert to ePub or a number of other formats using Calibre.
On Windows, Balabolka will open and read unencrypted PDFs. Adobe Digital editions also works to display a reasonable text rendering if there is text in the file.
on iOS/iPadOs, Dolphin EadyReader and VoiceDream will both read PDF, the latter will also doOCR I think if you have the scanner app. the native Books app can open them too, giving you access to the Siri voices through VoiceOver or the Speak Screen feature.

read as in read out loud?