Several small functions within the application are missing: Why is it possible, for example, to move fields within a group, but not rearrange tabs, groups or fields?
How does it work?
By expanding the database structure more or less immediately. Changes are made visible mainly by the addition of the prefix „x_“ to a file name.
If a standard mask is supposed to be changed, a descendant will be created as soon as the respective screen has been expanded, and rephrased via an „Xpath“ function (for an explanation see https://en.wikipedia.org/wiki/XPath). Somewhat simplified, this means that Odoo will interpret the XML of the respective screen as a complete string, will search for the appropriate field and replace the string responsible for the definition with a new one.
If you look at a module developed by a human being, this may happen as well, but this is not the rule. I cannot judge whether these adaptations will reduce performance. However, if something goes wrong and you are depending on the human element to find and correct the cause of the error, I would not wish this task on anyone. Even with smaller adjustments this is a challenge, as the result generated by Odoo is hardly transparent and thus very difficult to read.
But of course this alone does not justify a „No“.
The much larger problem here is that these changes will be written directly to the database. Although this happens in the form of data records and not as a structural change, each error will have a direct effect on the current application.
Odoo Studio certainly has its advantages, but at least at the moment it is not yet the universal remedy that renders any programming obsolete.