Do not get your hopes up. All of the OSRS gold favorite MMORPGS both new and classical ones that have put up a variant have a very clear advantage that RS3 does not have, the’re Freemium meaning they are Free to Play with Pay to Win mechanics via MTX. F2P on RS is not that appealing and you’ll be hard pressed to convince the majority of cellular runescape players to spend money for a sub fee monthly just to utilize lamps/stars once the goal of mobile games these days is to entice whales that will spend huge dollars for advantage. And of course that the tick based battle system of RS is a turn off in comparison to many action packed time battle nowadays in MMORPG.
RS is the main website for all of RuneScape, therefore the whole runescape participant count there encompasses RS3 + OSRS (and previously + RS Classic before it closed down). Old School has its own homepage, so you can discover the total amount of runescape players online.
If you would like to understand the entire amount of runescape players online you need to subtract the OSRS complete from the total displayed on the page since there. The counter is merely obsolete because that is the way. Jagex would need to bring a new counter to address the misleading runescape participant count difficulty.
It is correct that runescape participant counts are diminishing, but I think this chart isn’t really representative of the overall runescape playerbase (e.g. a single runescape player can log in and another can log off, where the amount displayed on the RS site would not change in this case), believing that runescape players reside in different time zones and also don’t play each and every moment. The hiscores on the RS3 site provides the amount of unique RS3 subscribers (OSRS subscribers do not show up on here, unless they also play RS3 on the exact same RSN) which have gained more than 1,000 XP a month, as you can see here for Cheap Rs gold November 2019 (data around December 2018 is publicly accessible ).