This isn't as much of an answer but rather a comment:
I'm not sure how long Apple will officially provide software updates for macOS Ventura, but I will mention that my current late-2013 15" Retina MacBook Pro is still receiving security updates, with an update just this month (September) for macOS Big Sur, which was originally released 3 years ago. Separately, there was an update to Safari web browser, so Apple is still providing some support for a 3+ year old operating system running on a 10-year old MacBook Pro. Furthermore, most software developers will still provide updates and/or make their applications compatible with older macOS versions even after Apple officially stopped supporting the macOS version in question. For example, all the latest versions of Microsoft Office, Chrome, Safari, Apple Music, MATLAB, Intego AntiVirus, AutoCAD, Alfred, Notion, Sim City 4, Spotify, Zoom, Microsoft Teams, Adobe Acrobat, Adobe Photoshop, VLC, Steam, etc. are still compatible with macOS Big Sur and even older systems like macOS Catalina.
However, with Apple finally transitioning all its hardware to Apple Silicon earlier this year, I expect that future macOS operating systems will be compatible with Apple Silicon-only. When exactly that may be, we don't know, as it depends on how quickly Apple pushes the software transition to Apple Silicon-only.
The last time Apple transitioned its hardware, it was a 2-year transition from PowerPC to Intel architecture back in 2005-2006, with the last Mac operating system to support PowerPC architecture being released a year later in 2007 with Apple Mac OS X Leopard (10.5). That isn't to say Apple will immediately stop supporting Intel Macs, as the share of Intel Macs is much greater now than say the PowerPC Macs back in 2006, so the software transition will be a bit slower and more complicated.
I would expect that Apple will cease releasing newer macOS operating systems for Intel Macs sometime over the next 1-3 years, but continue to provide security updates for existing macOS operating systems running on Intel Macs for another 1-3 years after the operating system was originally released (i.e. macOS Ventura might get security updates until like 2024-2025).
At this stage, macOS Sonoma (macOS 14) is still supported by newer Intel Mac models, but as you said, your model is not supported "officially". "Unofficially" however, you may be able to upgrade to macOS Sonoma using OpenCore Legacy Patcher (OCLP) for older unsupported Intel Macs. For instance, my MacBook Pro can "unofficially" be upgraded to macOS Ventura, which will mean it will receive macOS Ventura's security updates for another 1-2 years, and this is on a 10+ year old MacBook Pro! One caveat is that we don't know when OCLP will be available for macOS Sonoma, but expect it sometime in the next few months. Furthermore, due to some macOS features being only compatible with Apple Silicon, there will likely be more compatibility issues with OCLP patch for macOS Sonoma.
From an application-support perspective, I don't think software developers will drop Intel Mac support for their applications anytime soon either, except those applications that were originally designed for iOS that can now run on Apple Silicon Macs using Mac Catalyst.
In summary, I don't think you should really worry about Apple stopping support for macOS Ventura anytime soon. I expect you will still be receiving security updates for a good 1-2 years, judging on my own experience getting security updates for the 3-year old macOS Big Sur. If you're really concerned, you could consider upgrading to macOS Sonoma with an OCLP patch, but that may bring a whole lot of new compatibility issues down the track, which we won't know until it's been released and fully tested.
Finally, expect that Apple will stop releasing future operating systems for Intel Macs in the coming few years, but note that software developers (with the exception of iOS/Mac Catalyst developers) will probably still make their own applications compatible with older macOS operating systems and more broadly, Intel Macs for a good few years, even after Apple stops supporting them.
On a side note, I firmly believe Apple should stop releasing new operating systems every year and slow down to a 2-3 year cycle. It does not have to match the pace of iOS versions, because it's on a whole different scale Macs compared with iDevices.