Most agencies that offer Magento development arrived at it recently. We started on Magento 1 when it was the only serious option, moved clients through the Magento 2 rebuild, and were building headless Magento storefronts while the rest of the market was still theming.
That history matters in three practical ways.
We have already made the expensive mistakes. Magento punishes shortcuts slowly — a custom module written against the wrong extension point works fine until the next upgrade, and then costs more than it saved. Our code is written to survive Adobe's release cadence, because we are usually the ones still supporting it two years later.
We know which version you actually need. A great deal of Magento work is sold as a rebuild when it is really a performance problem, or an integration problem, or a merchandising problem. We would rather scope that honestly and do less work than sell you a replatform you did not need.
We can prove it. Oliver Bonas across 70+ stores. Topps Tiles across 332. Sanderson Design Group across six brands. LeMieux across ten sites. These are the numbers we can name, with the clients attached.