As soon as you buy a fender it's used and it's worth hundreds less. Worse yet, you mostly don't even lose said hundreds on cheap instruments.
In terms of percentage, boutique brands are going to save most of their worth, but higher end fenders, ibanez, etc, don't come close in terms of resale value, and worse YET, cheap guitars, although losing more value percentage wise, still end up losing less of the actual value. Hell, even a boutique guitar that loses $500 of its value over time will cost you more than reselling a cheap knockoff, and here's why:
You can sell a used GIO bass/guitar for $100 if it's in good condition, even though you bought it for $200 new. That's a crazy 50% price drop! Even if you end up selling it for $50, which is likely considering those end up being (ab)used by the time they are sold, that means you lost $150 on the trade, which is 75% of the value!
But if you buy a new ibanez prestige for $1500, you're likely going to sell it for no more than $1000, so you lose 5x as much money by selling a gsr180 in a good trade, or 2.5x as much in case of a bad trade for GSR180.
Hell, even if you end up selling the prestige for $1200, which you likely listed it for, then you're losing $300, which is 1.5x the total price of the gsr180!
I have no idea where this "you lose less money on trading high quality gear" myth comes from, it's really weird that people who spread such nonsense don't think twice about this. When there's more money involved, you lose more money, it's that simple. Even if ratios shift in favor of high end gear, the actual amounts are completely different.