In fact, osCommerce is unusable without the Addons.
Congratulations! You have inadvertently stumbled upon one of the main reasons why osC flat-lined.
The osC Marketplace is saturated with old & expired addons that are poorly coded with little to no conformity to any osC coding standards. Then there are the Zombie Phoenix addons and addon updates that support a spin-off eComm software. And now, it is no longer monitored so we have spammers posting garbage like the two screenshots below. Additionally, the search feature stopped working in Firefox for some reason, though it still works in Chrome. And you want to keep this? Really?? smh
I think that all addons for version 2.2.x should be removed. If you have osC v 2.2 on PHP5.x, you have gravely neglected your store and you are not doing any justice for your customers.
All addons for osC v2.3.x should have a 12 to 24-month end-of-life time-line starting with the release date of osCv4. This gives everyone time to either download the addons they still have not for their legacy version, or switch over to v4 if they chose to do so. osCv4 addons should be completely separate, tested, and monitored for quality, code conformity & consistency, and relevance/usefulness.
However, if osCv4 is going to adopt the same failed business model as its predecessor, then by all means, keep the Marketplace as is, ..and all the issues and store-owner dependencies that come with it. Applying the same methodologies of a software that flat-lined, to a software refresh is the definition of insanity. That's a reference to an Albert Einstein quote.
Personally, I have a lot of time & effort invested in all the addons that I contributed to osCommerce over the years. Regardless, I have no attachments to them and would gladly let them all go just to see osCommerce start fresh with a new slate and a better market & business strategy.