Owning multiple toons in Lineage 2, is not always a good thing. Especially when those toon have gear that you can sell. Sky is the limit for the game, new and expensive items are always added and we have to keep up with it, for the most part! Contrary to what many may think, you do not need everything +10 to have a decent toon.
The reason it is not good when having gear is that when a good opportunity presents, we always try to sell something from “an alt” depending on value, this might be just one or more items and that is something I have done myself, on multiple occasions.
Now why you would need multiple toons? Some free Events, Attendance Rewards, Anniversary Rewards start to slowly build on each toon you log in, which results in having a bit of gear and enough damage to be able to farm instances and make adena.
The whole process can be done for FREE but it takes time and patience. Not everything will come easy and some times rewards that were given in the past are a one time thing! It is possible you missed out on something good but eventually, you will get something that someone else will miss out on.
Since the game started, we all had 1-2 extra accounts, some had more but you need a buffer or 2, a healer, possibly a tank depending on your class, others have extra damage dealers and with the free items they handed out on the 20th Anniversary, it made the whole project a lot easier, a free Blessed Exalted Set and a Greater Rune Stone are a huge boost for every free to play toon, add the rest of the free rewards overtime and all you need is levels both on main class, as well as the dual.
There was a rework on Tanks, Healers and Enchanters in 2024, most of the unique buffs have been reworked, and buff effects increase as the players level increases, with 120 being the last available upgrade on buffs, so you see there is one incentive to have toons that are high level. I would say that 115 is the sweet spot for alts both Buffers and Damage Dealers but keep in mind that now ALL toons are damage dealers, all support classes were reworked and the majority of the toons can stand on their own, some have more expensive builds than others but for the most part even an Enchanter can do content around the characters level, assuming there is gear on the toon.
Having multiple toons is more than a simple task of logging them in or having them in party with your main toon so the get levels. Knowing each skill, different builds and how to get the most of each toon is something you learn over time. When you begin to fully understand that