There are various reasons why one does not immediately improve pages to meet certain standards, or even to prevent deletion. If an editor states an intention to make an improvement that will take more time, this should be respected.
Researching an important topic
Sometimes, an improvement will require time for researching information on the topic at hand. This may include finding and studying books, newspapers, journals, or web sites, choosing the most appropriate sources, or summarizing material in encyclopedic form. Rome was not built in a day; neither is Wikipedia.
Other Wikipedia activities
Many editors are busy with creating or editing a series of articles or other materials, or making other improvements to Wikipedia. Others are happier working in behind-the-scenes areas of the project, such as removing vandalism. An unrelated matter may have to wait.
Some editors have other hobbies ...
... or work that must take priority
Some people may be dedicated to Wikipedia as their number one cause in life. For most editors, however, editing Wikipedia is akin to a hobby that ranks lower in personal importance than editors' personal lives and their employment, family, health and other factors. Real life usually takes priority over editing Wikipedia.
Because Wikipedia is completely voluntary, under no circumstances are editors obliged or expected to make any edits, respond to any messages, or to otherwise have any involvement. Please don't presume you have offended a fellow editor who has not responded to your message, or that they are insulting you: assume good faith
and remember life might have gotten complicated. By drawing negative inferences from their lack of editing, you might be making it less attractive for them to productively contribute to the project in the future.
Editing Wikipedia is often one among several hobbies. An editor may spend months playing video games, hiking, reading, visiting friends, or watching the grass grow. They may show up to edit Wikipedia whenever they feel like it.