Good points The End, and welcome to the Piggs.
Quite right that a lot of flipper properties show hastiness and superficial improvements, while a deeper look will reveal an inferior job that, in truth, should not add much to the market value. Of course, to the seller its perfect, and should be priced accordingly.
On a related subject, I’m a big believer that an “improvement” should not be made until the existing component is really past its useful life. In the example cited, windows in a 1990 house were probably already dual-glazed. Only if they were single-glazed are they truely obsolete and deserving of replacement. Likewise, 20-year old stucco should not need paint or replacement. A 20-year old kitchen and bath? Probably OK unless this house is in a super location and deserves the huge expense of dealing with K’s and Ba’s. Another factor, when the seller does all this work, their designs and color choices do not necessarily match that of the target market. Better to let the buyer decide these choices and keep the selling price low as a result.