I remember when I had an 850 FICO score. Good times. When I paid off my installment loan my FICO score gradually fell until it reached the upper 700s. It's been stuck there ever since. Sometimes I'd get to 800 or a little over but with no installment loan my FICO score was extra sensitive to whatever credit card balances I had. Now that I have a small car loan I can't get back much above 800 because it's too new at 1.5 years out of 5.
Keep in mind that VantageScore is not worth much. Almost nobody uses it. You need a FICO 2, 4, 5, or 8 score. Amex will give you a FICO 8 score free from Experian. Discover will give you a free FICO 8 score from Transunion. My Experian is 808 and my Transunion is 796. On Credit Karma it says my Transunion VantageScore is 819 so a 23 point difference. FICO 8 scores are almost always higher than the older 2, 4, and 5 scores sometimes by 20-30 points. Those older FICO scores are used for mortgages. The 8 is used for credit cards and auto loans.