No, that's a myth spread by fascists to draw attention away from them. We can't let people who are only performatively left wing define it. You wouldn't like it if people started judging you just because an identity thief said your catchphrase and did a hit and run, so please use common semse when people claim to be something. Why are they saying those things? Does it match their actions? Could they be lying? What are they trying to achieve?

My husband and I still feel in love after 18 years, however we both never stopped putting effort into showing the other person multiple times per day that we loved them so perhaps the continued feelings just followed the continued actions. It probably also helped that we were polyamorous for the last 15 years, so finding other people attractive has never been something that would require us to break up, and also means there are no feelings we need to shove down or ignore in order to stay together. There is also a difference between the obsessive love ("limerence") that is present during the honeymoon period, which is a good thing it doesn't last (your brain has other important things it needs to dwell on besides your partner), so limerence fading does not mean that you don't love that person anymore. But if you are both not putting in active effort, I can see how your attraction to each other can wane. I wouldn't want to be with someone who isn't putting in effort, but is staying with me anyway because they decided they ought to be faithful, that just sounds like it breeds resentment. Loving someone should not be about what you do or refrain from doing outside of the relationship, but about what you do or don't do inside the relationship. But I do agree with the clip - if you're no longer interested in putting the effort in when you are with your partner, it's kinder to just break up sooner even if it makes you look like the bad guy so that they are free to focus on finding someone who will put in the effort, rather than leading the person on.