This isn't so much a question of "Do you have the best speakers," it's more do you have the right speakers? Do they make you happy, or are they just getting by? If your Sonos Play:1 speaker rocks your world with Adele, Beethoven or Sufjan Stevens, that's great, but if music isn't making you happy, you might need something better. The Play:1 is a perfectly good speaker, but it might not be the best speaker for you.
As a reviewer I get to live with a lot of different speakers, and I've noticed that some lead me to play different kinds of music. I have a large, eclectic collection, everything from beatnik jazz to Frank Zappa to classical, world music and electronica. Now that I'm in the midst of reviewing the big Harbeth 40.2 monitor speakers, I'm playing a lot more hard rock, because these speakers handle loud music with greater ease than my reference Magnepan .7 speakers.
Speakers all sound different, so it shouldn't come as a big surprise that they accentuate different aspects of music. For rock and a lot of pop that's best played loud you need one kind of speaker, but classical music rarely sounds best on speakers that excel with rock. With classical music a natural tonal balance and low distortion are top priorities, with rock, dance or hip-hop it's more about impact and dynamics.
If you like loud music, do your speakers sound great played loud? Or if you like to listen quietly, do they sound fantastic played low? If you crave bass, do you get enough at home? In other words, it's not how "good" your speakers are; do they speak to you and your needs?
It's how the speaker(s) make you feel, do you connect with your music, or is the music all too easy to ignore. If the music draws you in, you're on the right track; if it doesn't you need new speakers.
I know some folks think a "good" speaker should play all genres equally well. That might at first make sense, but in practice different speakers have very different strengths and weaknesses.
Speakers play the room
Room size and acoustics should be considered when shopping for speakers. For example, a pair of bookshelf speakers like the excellent Klipsch RP-150Ms will sound very different in a small room with thick carpeting and overstuffed furniture, than these speakers will in a loft with lots of exposed windows and bare wood floors. The variables of the speaker/room interface are huge, but small speakers work best in small rooms, or if they only need to be played quietly, or bass oomph isn't a priority. Large speakers do better in large rooms, and/or where high volume or massive amounts of bass are desired.
For a small kitchen, bedroom or office, will a Bose Soundlink Bluetooth Speaker III be all you need, or would you be better off with a pair of Pioneer SP-BS22-LR bookshelf speakers and a cute little Dayton DTA-120 amp? It's your call. The Pioneer/Dayton system will sound a lot better than the Bose, but the Bose is a single wireless speaker; the Pioneers are wired, and must be connected to an amp.
A pair of speakers, placed 5 or more feet (1.5 meters) apart, will fill a room better than a single speaker. Two speakers may be one too many for some users, but two good speakers will always sound better than one good speaker.
So where does this leave you? When shopping for speakers, consider first where you're going to listen, and how loud or soft you like it. Of course, a home audition would be ideal.