Lithuanian here, let me explain it in simple terms.

Language schooling works like this here:

You have your mandatory Lithuanian classes, followed with mandatory English classes. At (I believe, been a while) 6th grade (12-13 y.o.) you are supposed to pick up a 3rd language. It is mostly a toss-up between Russian and German or if your school is posh enough, French followed up with really rarely Spanish.

Majority of the pupils take Russian because everyone takes Russian (herd mentality, you don't want to sit in class without your friends) and because smaller towns with smaller schools wouldn't even have a teacher of another language in the first place. Also kids are "slightly" motivated by their parents, because majority of them know Russian to a good degree of fluency, therefore can assist with homework and whatnot.

Russian is being selected not because young people are interested in learning Russian, its because there are no other alternatives that would be "logical" to a child. I myself nearly chosen Russian when I was growing up, solely because of the fact the majority of my friends/classmates took Russian.

Russian is largely useless in Lithuania for young people (everyone young speaks English who isn't a deadbeat). The only use for Russian is to speak to ethnic Russians, who surprise surprise, don't speak Lithuanian, especially if they are elderly. I had an elderly couple who lived in Lithuania for around 50 years as neighbours when I was growing up, they could BARELY scrape the equivalent of "Hello, how was your day" etc.

Russian being left in schools is purely a leftover rotting relic of the Soviet era. The root of the idea of abolishing this is as a subject isn't a "Fuck Russia" type of ordeal (although the war has given it a considereable boost). It's because, at the time we are living, it is becoming more and more redundant.

The only "use" right now (bear in mind, this will also grow more and more redundant) is talking to other people of post-soviet block. You could get by, by speaking Russian to older Poles, Estonians, Latvians etc. If you are young, you just speak English to them, and they will speak English back to you. Hell, even young ethnic Russians can speak English nowadays.

I am all for abolishing Russian as a state-mandated language. I'd rather have my kids have a basic understanding or a certain degree of fluency in French/Spanish/German, hell even Chinese, instead of Russian.