It may just be possible.
Monero is one of the best privacy tokens. It has been around for a long time and the team is consistently plugging away at their development initiatives. Privacy tokens are really desired by the cryptocommunity and while several projects have show promise (Zcash and Spectrecoin for example), Monero has established itself as one of the front runner.
But can it outshine Bitcoin in the next 5 - 10 years? That's a big development. I love what Monero is doing, and it is really filling a void that Bitcoin does not. People, especially newbies to crypto, forget that Bitcoin is pseudonymous, not anonymous. It's going to do well as privacy coins become common in usage, but Bitcoin still takes the cake in terms of actual use for day-to-day transactions. However, I feel that for very specific use cases, Monero will take over some of Bitcoin's territory.
The sense I get is that when crypto reaches more widespread adoption, the average person who has just entered crypto will see that a privacy token like Monero exists and for whatever reason that he or she may use the privacy token for, the option exists. And that option will be preferable to using the pseudonymous token that is Bitcoin.
And I think one catalyzing factor in this will be the realization of individuals that data leaks are plenty and have staggering consequences. Facebook, Equifax or what have you make a worrying impact on the financial and social lives of individuals, and people are beginning to realize that they should protect their data - and when this realization grows among the public, and people get into crypto, Monero will be one of their choices.
Now one question may be whether Monero can do well when there are several privacy tokens being developed. It has a good headstart over other projects, and a strong team and development progress, which ensures that when privacy tokens do find demand in the future, Monero will be up there at the top.
Comparing tokens to Bitcoin is a little unfair, given that Bitcoin is the originator of all of this and that it has the most widespread adoption and use. I think any token that manages to eat away a little at the market share of Bitcoin should count itself victorious. And I feel that Monero may find a little victory in the near future.