I would love each kind of spellcasting focus to grant a different spellcasting benefit. I would need these benefits to robustly balance with each other and be equally good choices.
Delete spellcasting "components" from the game. Instead, only the focus matters. Decide which focus the character concept is using.
Examples of focuses:
• Mind (trance, mystical experience, visualization, etcetera)
• Voice (improvising expressions of intention, chant, song, poem, command, reciting formula, etcetera)
• Body (dance, Airbender, nose wiggle, hand signs, magic-infused body, drop of blood, etcetera)
• Symbol (personal, traditional, sacred, necklace, tattoo, shield, etcetera)
• Text (personal, traditional, sacred text, diary, book of poetry, written oracles, spellbook, etcetera)
• Implement (wand, staff, rod, cane, distaff, orb, sword, musical instrument, etcetera)
• Components (protoscientific properties of various objects, animal/plant parts, tarot deck, etcetera)
• Pet (familiar)