I maintain 1K and SE as both programs have their own benefits. 1K is nice for economy plus and free food and drink in the back as well as confirmed upgrades on purchase when using GPU or RPUs. Is also great for no fees for stand by, same day change and reward changes. While it used to be that UA filled the front cabin with free upgrades, that definitely isn’t a benefit I value much. Most times when I fly it is filled with cheap last minute sell ups that are marketed to everyone. Most popular travel times unless the front is almost empty UA will not confirm an upgrade until 24 hours before and usually even as a 1K I am way down the list. If you have fly enough revenue to make global services you may more relatably get upgrades.

On AC I have fewer upgrade credits but at least at the window I usually clear or a few days out and although they sell upgrades through bids they don’t sell as cheap and have left enough that as an SE I can usually get an upgrade.