Do you think cardano will over take ethereum in terms of tech with voltaire being worked on this year. Along with erc20 converter for easy conversion to cardano via ethereum. 
No.Since when cardano has been launched? It had a lot of years to overtake ethereum and just as the heavy investors of it think about it, there's nothing new to this discussion because it's most unlikely not going to happen.
I think that this topic already outdated.
That's true, this is an old topic that's just being repeated and being asked again and again. Soon when the bull run comes, if it's not ADA, it will be another altcoin that will be asked if it can overtake bitcoin or ethereum.