Get into a ute mate.
It's a horrible feeling being all squished up with your tools inside the cabin with you.
Buy a car fit for purpose, a wagon is to move families, not to move tools.
I find it ridiculous when I see house painters etc with wagons full of paint tins, rollers, brushes etc. The inside of the car would look like a mess pretty quickly. I'd also never hire a tradesperson that couldn't afford or didn't want to buy a vehicle that was suited to their work, that rings red flags for me.
I get the boomers loved to have their wagons as family/work vehicles but these days there are so many options that are better suited to trades.
I agree with some of your logic. However, I’ve used a couple of Falcon wagons over the years when doing property and building maintenance, carrying all manner of tools. Taking the back seat out allows the back rests to lay flatter, and putting in a 6mm sheet of MDF sculptured around the sides works as a good smooth base.
On occasion when needing to use the car as a family wagon, I could take everything out and replace the seat easily enough.
A wagon roof rack was handy for ladders and certain lengths of timber and such, and easily accessible..
As mentioned by rambunctious, a cargo barrier will stop anything from smacking you in the back of the head when having to slam on the brakes etc.
Yes, there are drawbacks as you mentioned. Having your tools and equipment stored in an organised manner is a must and can be a pain in the arse when things get out of hand. But hey, have you looked in the back of some tradies’ Utes and vans?