I quit somewhere around Tele-DAD being popular and ran Lightsworn myself. The introduction of Synchro really changed the pace of the game. Did it speed up more since then?
Oh yes, massively so. In the last few years we got quite a few cards/archetypes that can do so called "turn 0 plays", meaning you can perform a lot of actions even on your opponent's first turn.
This adds even more complexity with the upside of preventing players from playing solitaire on their own for 10 minutes before passing an unwinnable boardstate to you.
Also most floodgates that grind the game to a halt (Gozen,Vanity's emptyness etc) are either banned or limited.
I'd say the game overall is very fun nowadays, but the original "design space" is starting to hit a ceiling with absolutely bonkers effects being printed that literally cannot be one-upped with the current rules. Read the text of Forbidden Crown to get what I mean.