MacBook Air 2014 Safari 10.1.2 will not update - tried all things - can't function properly with safari as is

About all you can do would be to upgrade macOS to newer supported Mac system.

Then, that would have newer Safari version, than the older one had included within.

• Update or reinstall Safari for your computer - Apple Support

https://support.apple.com/en-us/HT204416

"To keep Safari up to date for the version of macOS you're using, install the latest macOS

updates. The most recent version of macOS includes the most recent version of Safari."

Other ideas for more recent web browsers, have & use supported updated third-party

known quality browsers, available for download; from Mozilla Firefox, Brave, Opera, etc.

To get a newer or latest supported macOS version, a downloadable system installer, see:

• How to get old versions of macOS - Apple Support

https://support.apple.com/en-us/HT211683

From Mojave 10.14.6, forward, are most likely to see Security patches; older are less likely.

The links show progression of upgrades; yours can use 'Catalina'; maybe not Big Sur.

A matter of other considerations may keep you happier with Mojave 10.14.6 & 32-bit/64-bit

compatibility; seems well in my Mid-2012 MacBook Pro; which may only do OK in Catalina.

[For those with Safari browser updates, method would be download full macOS/installers.]

Here is some information you should know. I think I can explain what is happening. If you are unable to access certain web sites and getting a message that your browser must be updated, this is not an unusual situation. The reason is that web site engineers write their software to work with specific browsers and specific versions of them. You can hope that your web site's developers eventually update their site to work with Safari, or you can use another browser that does work such as Firefox or Chrome. They can be individually updated as needed. It is important to know that Safari is installed as part of the operating system and it normally it cannot be individually updated. Safari is periodically updated when the computer's operating system (OS) is updated or upgraded. Finally, even if you are able to update Safari, there is no guarantee that it will be compatible with every web site. This is why many of us have more than one browser installed.