It is not entirely about stat growth; because a good number of games which are clearly not RPGs have experience and star growth - including many fighting and sports games (like MMA games).
The term RPG was popularized in Japan long before it was popularized in the west - games like "dungeons and dragons" were called "RPGs" almost exclusively in Japan, but were popularly referred to as "pen and paper games" in the west. Role playing games in the west referered largely to psychological exercises in the west. Videogames that resembled pen and paper games would be which we commonly referred to as quest or adventure games in the west; RPG is not used in our magazines for these games. In Japan they were called "RPGs". That eventually spread over here too once games like Final Fantasy titles became popular. Terms like "JRPG" and "WRPG" were only created in the last decade or so, as they didn't appear anywhere until after the launch of Starwars Knights of the Old Republic. Common usage of the term "RPG" in the west was largely limited to describe turn-based RPGs like Final Fantasy, until people decided they wanted to call action games with similar traits RPGs too; and some even wanted to call Ocarina of Time an RPG.
Anyway, for an RPG - you can make an argument for almost every game to be an RPG nowadays - so there are some boundaries that should be noted: the gameplay emphasis should largely be based on the stats and not action elements; a turn based game which uses RPG element is is always an RPG; because the RPG elements fully determine the outcome. An action based game which uses RPG elements might not necessarily be one; For example, an MMA title with experience and stat progression still has the emphasis of success on action based skill - and not on the stat progression - is not an RPG. A game like secret of Mana where action is part of it, but your stats are more important to the outcome would make Secret of Mana an RPG...
On the other hand, this would exclude Terranigma which is clearly much more based in skill - and I am fine with that because Terranigma has much more in common with the game it is a sequel of (Illusion of Time) which is clearly an action adventure with a story. Although, despite having no experience points, and less of an inventory system than Legend of Zelda Link to the Past and higher, Illusion of Time is often called an RPG - but in reality, Illusion of Time and Terranigma are action adventures.
I describe myself as a little dose of toxic masculinity.
