Getting files on and off of a phone is shockingly hard. Shockingly. It's even worse on an iPhone, if you don't have a mac. To get my photos from my iPhone to my PC, I had to first upload them to iCloud and then download them again. My phone and computer are, like, a foot away from each other but I had to send the photos across the country to some server and back just to look at them.
KDE Connect may work for you. (You don't have to use KDE.)
Oh, I use use AirDrop to myself for this. Yes, given my photo library syncs to iCloud, just opening Photos seems like it makes sense on a fast WAN which I sort-of do have, but of course, iCloud syncs only happen when the device decides the mood is just right, and can't be triggered manually, because I guess that would just be 'clutter' in the UI.
LocalSend works really well across platforms in a LAN, no uploading to some server required.
That's mostly an iPhone problem. Plugging in an Android phone still works, and wireless exchange with QuickShare also works on most devices. With Google reverse engineering Airdrop, I hope they can get the Android <-> macOS experience to finally work correctly soon as well.
My only real use of Google Keep is as a cross-device clipboard.
I personally just have a discord with myself as the only member. With their webhooks API you can even automate the PC side.
I emailed myself many times to transfer some files between phone and computer. I would say at least once every week.
I'm super techy but I admit that I just use Signal to send me a "Note to self" whenever I need a file from my phone on my computer quickly. For images I just use immich, but texting myself is honestly the quickest way for files because the experience is indeed terrible.
It is a solved problem https://f-droid.org/packages/com.ismartcoding.plain/
There is also localsend, but plainapp needs to run in only one device.
You can just use Dropbox or equivalent.
Everyone emails themself stuff, that's normal. The weird part is how often will you ever need to email it specifically from your laptop, but it's already on your phone? If it's on your phone and you need to email it to someone, couldn't you just email from your phone?