We have many Target activities running on our website, and there are some that are no longer necessary. Would leaving those activities on impact the overall performance of the website, or the page it is running on?
Example: An activity generates a small button on a page that is only accessible with a specific query string parameter. The query string parameter is no longer possible to generate, so the Target activity is not accessible anymore, however is still Active/Live. Would it still impact the performance of the page?
Let me give small overview from whatever I've understood till now by working on Adobe Target.
You can say Adobe Target is just an platform to inject your code into website or app with added advantages like creating audience, customer attributes, profile scripts etc. and nothing more different than development tool with advance features of targeting customers more effectively.
Whatever offers you create in Adobe Target console are delivered on your web pages in the form of JSON.
If you have too many activities running on page it won't affect a lot on page load unless and until you are adding too many heavy custom codes in target, creating unnecessary objects, non ending loops or code which is taking more server memory. Also adding too many inline CSS and js files using target and render blocking scripts may cause increase in page load.
I think using target functionalities in proper way will never cause load time issue.
So affecting page load time depends lot on how you are using Adobe Target and what things you are doing through Target.