Poor image quality when taking photos with Lightroom mobile app on phone

I hope someone can help - I've looked through the forums but can't find a question covering my query.

In a nutshell, I find the photos I take on my Google Pixel 3a to be better then ones I take using my Lightroom app, both in jpeg and dng formats.

There, I've said it.

In years gone by (post film photography) I've always taken RAW files on my dslrs, and processed accordingly.

More recently, with the massive improvements in camera phones, I find myself taking more photos with my Pixel 3a (in addition to my old 35mm & medium format gear) having now got rid of my dslr equipment.

So my natural assumption was that dng files via LR would be superior to jpegs from my phone. 

I've done some controlled captures of both (including LR jpegs as well) and the Pixel 3a's images look noticeably better (exposure/contrast/colour/sharpness/noise) than either jpegs or dng files form LR.

I've tried to process the dng files to the best of my knowledge and experience but can't get them anywhere near the Pixel 3a's jpegs. Although I admit I'm not the greatest photographer/post processor/printer in the world, I have been doing it for a lot of years (at one point making my living from it).

Now the obvious answer to this is that my file processing is not good enough, however there are (at least) two points to note: 1. If it isn't, I'd be more than happy to get advice to improve my processing technique; 2. Is it reasonable to expect to have to take dng files, and carry out all the associated processing, in order to achieve results that match jpegs straight from the Pixel 3a?

For what it's worth I also did a comparison between my phone, LR app, and my Lumix DMC-TZ70, and my phone came out a clear winner (I appreciate the tech in my Lumix is now several years older than that in my phone).

I've been struggling with this for a while now. I'm hoping that I'm so stupid that someone will point out the obvious thing I've been missing.

Or have other people had the same experience, and will just tell me that phone image capture & processing technology has improved significantly over the years?

Aa a means of image capture is my LR app surplus to requirements???