If you're running Windows 7 on a laptop or Desktop, should you be concerned? No
If you're running Windows 7 on a mission-critical machine that Windows 10 won't run, should you be concerned? Eh, not really..
Millions of machines around the world are still running Windows XP. These machines are very expensive and run fine on XP. Many of these are in the medical imaging field or manufacturing. Replacing these machines before their end-of-life cycle is not cost efficient for hospitals, and sometimes not at all possible in manufacturing. Your last Ultrasound or MRI was probably run on a Windows XP machine.
Windows 7 was a big step in the functioning of Windows. Many programs that ran fine in XP would not run in 7. Likewise, many programs that run in 7 will not run in 10. So why not be like the hospitals and stick with what works?
Frankly, it makes sense to just keep using 7. Windows 7 was the last "offline Windows OS." Windows 10 is slowly migrating to being a full online Software as a Service system. It's a hybrid now, with login using an online account and Office being run from Microsoft servers.
In a few years, Windows 7 will be viewed as the last operating system to empower people to be creative and do what they wanted with their computers. Windows 10 is slowly removing power from the user over the PC, locking out files and processes in the name of security. And while this does improve security, it also decreases functionality. It won't be long before Windows is as limited as Android, your programs have to come through their Store, and Microsoft collects your data to sell, like Google and others.
So why stick with Windows 7? If it does what you need, keep it and don't waste the time upgrading and the hassle of figuring out why it doesn't work after every Windows 10 update.
SO, here's the caveats.... You need to do a few things to make sure Windows 7 keeps working. First, BACK IT UP! Not using Windows Backup, but a 3rd party backup program like Macrium Reflect Free or Paragon Backup Free. If your system gets corrupted, you'll need an image to restore it from. Using the Windows Backup, it won't backup your activation and you'll need to activate it again. But this hasn't been possible for a while now since Microsoft turned off their activation servers for 7. So use a backup program that will image the drive used-bit by used-bit and when you restore the image, Windows 7 should be activated.
Also, use the backup program to create a bootable DVD so you can restore the backup if something happens to your hard drive or system files. Most backup programs come with the utilities to create a bootable DVD/USB which is what you'll need if your 7 won't boot.
Anyway, with activators around that still work for Windows 7, this will be your only way to get it activated before long and you'll have to disable the antivirus to download it and install it. After using it, turn the antivirus back on and do a thorough scan of the system to make sure you weren't compromised. Do a boot sector scan also.
That's the next issue, keep your antivirus up to date. Stop using Windows Defender or Security Essentials and switch to Avast. Their free version does great and will help protect you from all the vulnerabilities everyone will be crying about and using as reasons you should ditch Windows 7. Keep Avast up to date and you'll be fine. Use the Avast Safe Browser if you want extra protections for that precious 7.
Anyway, whether you need to stay with Windows 7 because you have mission-critical non-10 compatible software on your system, or you just don't want to fool with fixing Windows 10 whenever the update crashes your machine, Windows 7 will last long into the future and function just fine.
Of course you could always switch to Ubuntu or Linux Mint and not fool with the Microsoft hassles at all. A vast majority of power-users will be doing this in the future as they see Windows removing functionality with each new Feature Update. Many Linux distros function just as well as Windows 7 and easier than Windows 10. They are a viable Windows replacement. Check out https://www.distrowatch.org/ and find a favorite Linux flavor! (Test the Linux distros on a USB before installing over Windows, lots of help for this on Google)