Well maintained plugins may be updated quite frequently. Developers that follow WordPress guidelines and other applicable best practices will generally release stable updates that are safe and worthwhile. Nevertheless, the dizzying array of interactions that any given plugin is expected to support essentially means that even the best developers will occasionally release a plugin (or a plugin update) that causes issues when interacting with other plugins, the newest version of WordPress itself, or something else installed on the server. And, of course, not all developers are as capable or careful as these best.
For this reason, every update needs to be tested as thoroughly as possible before installation on your live site. Ideally, this testing is completed in a special test site (and possibly also in a staging site), then, if all is well, it is installed on your live site and tested yet again. Your webmaster does not want you to accidentally break your own site with an incompatible or broken update. Consider yourself fortunate to have such conscientious webmasters, and do nothing to pressure them to abandon their excellent process.