They are significantly worse. There is absolutely no comparison.
1) Phones combine actual essential features with “time killers”. With a TV or arcade games, there was no illusion of those activities being essential in any sense. So the easy response for both of those was to limit access time. You cannot do that as easily with modern phones (these features are an attempt to do so).
2) Availability. Your phone is with you all the time. Because it is portable and it is personal. A TV was usually shared and rarely portable like the phone. Same is true of other major time killers.
3) Variety. Phones have a much greater variety of addicting behaviors. It’s like taking a super charger TV, arcade games, and a whole host of other new addicting features (e.g. social media which in addition to the dopamine hits has built in fun peer pressure aspects necessitating their use amongst kids), throwing them in the same device, making it extremely portable and available, and then throwing in some essential features (messaging/phones) so parents have to make them available to kids, and until recently providing no decent ways of limiting the usage.
4) Data and dopamine hits. Almost every other “time killer” until now has had to target a fairly broad demographic but today’s apps and social media sites, etc have the smartest brains in the world sitting around plotting how to get adults and teenagers hooked onto their service based on their individual usage. I’ve quit FB but noticed that the app spent the next month spamming me with a variety of notifications trying to figure out what would get me to open it (a birthday reminder did the trick) and then spammed me with birthday notifications until that stopped working and went back to a variety of notifications again. TV never had the ability to target individuals to this degree.